I feel this, especially since I'm more into networking, but my work is more generalist.
I open my mouth about networking and people's eyes glaze over. Even very experienced senior people can't really understand what I'm talking about when it comes to some of the more intermediary networking concepts. Meanwhile I tune into a podcast that's networking focused and they're basically speaking Latin for me.
There's so much that I don't know. I get the broad strokes of things but I'm hopelessly lost on so many of the more nuanced bits of networking.
I really want to break away from generalist work and get into a network focused position, but after 10 years as a generalist in various MSP companies, most places won't take me seriously as a networker and won't even sit down for an interview.
I'm good at other stuff, damn near expert level with some things, but my passion is networks and the workplaces I've been at just don't care to help me learn any of it. My current place barely has any networking more complex than a profile based L2L VPN.... Switches are basically ignored, and VLANs are rare.
I facepalm every time I discover that the guest network is just bridged into the same subnet as the LAN. I've raised the issue a few times and never been given the green light to fix it, often because the network isn't able to be managed remotely.
This is why I can't work in an office. The last one I worked in, people kept waking up to chat "for a sec", when it took at least 10 minutes regardless of the inquiry.
Just as I'm starting to get myself back into my workflow.... "Hey, you got a sec?"
Sure, looks like I'm not going to get anything fucking done today, so why the fuck not. The only people I'm disappointing is the employer. I can have a chat. It's fine. Not like this will negatively affect my ongoing employment.
I've been doing IT work for more than a decade, I was a nerd/"computer guy" well before that. I've had a focus on networking in the past 15-20 years. You learn a few things.
I try to be humble and learn what I can where I can, I know that I definitely do not know everything about it, and at the same time I try to be generous and share what I've learned when I can.
So if you have questions, just ask. I either already know, or I can at least point you in the right direction.
It definitely sounds like you have some challenges ahead. I personally prefer MoCA over wireless, simply because you can control what devices are able to be a part of the network, and reduce the overall interference from external sources and connections.
With WiFi, being half duplex, only one station can transmit at a time (with come caveats). Whether that station is a part of your network, or it is simply operating on the same frequency/channel, doesn't matter. So in high density environments, you can kind of get screwed by neighbors.
MoCA is also half duplex (at least it was the last time I checked) so having a 2.5G MoCA link, to a 1GbE connection (on the ethernet side) should provide similar, or the same experience as pure ethernet (1G full duplex)... The "extra" bandwidth on the MoCA will allow for each station to send and receive at approximately 1Gbps without stepping on eachother so much that you have degraded performance.
However, it really depends on your situation to say what should or shouldn't be setup. I don't know your bandwidth requirements, so I can't really say. The nice thing about ethernet is that it on switched networks (which is what you'll be using for gigabit), the. Ethernet kind of naturally defaults to the shortest path, unless you're doing something foolish with it (like intentionally messing with STP to push traffic in a particular direction). The issue with that is that ethernet doesn't really scale beyond a few thousand nodes. Not an issue for even a fairly large LAN, but that's the reason we don't use it for internet (wan side) traffic routing. But now I'm off topic.
Given the naturally shortest-path behavior of ethernet, of you have a switch in your office and you only really use your NAS from your office PC, you'll have a full speed experience. If nothing else needs high-speed access to the NAS, you'll be fine.
Apart from the NAS or any other LAN resources, the network should be sufficient to fully saturate your internet connection. So the average WiFi speeds should be targeted towards something faster than your internet link (again, half duplex factors in here). I don't know your internet speed so I'm not going to even guess what the numbers should be, but I personally aim for double my internet speed for maximum throughput on my WiFi as much as I can. The closer you can get to doubling your internet speed here, the better. Anything more than that will likely be wasted.
There's a ton to say about WiFi and performance optimization, but I'll leave it alone unless you ask about it further.
It can be faster, it really depends on whether you have a clear-ish channel for the mesh, which is why I would recommend something on the higher end, hopefully with a dedicated radio for mesh, so it can be on a different channel with (hopefully) less interference.
If the mesh radio is shared with client access, or if it's on a busy channel, it may be much, much slower than some options.
Depending on where you live and what your power circuits look like (not the outlets, the circuits that power them), you may have a great, or very poor experience.
I'd need to know what country you live in to know more, since power wiring standards vary from country to country. In the USA and Canada (I'm in Canada and the USA is the same), we use split phase and crossing the split phase will severely hinder the ability for powerline to perform.
It's a viable option, not my favorite option, I'd recommend MoCA (coax) over powerline, but it's ultimately up to you.
IMO, powerline is going to depend on a lot of factors including what kind of power you use, which varies from country to country. Where I am in North America, we use 240v split phase, and the powerline adapters are 120v (half phase), so if one unit ends up on one side of the phase, and one ends up on the other side of the phase, you're going to have a bad time, if it links at all.... So knowing which "side" of the split phase your powerline is on becomes critical, which is not something most people know about their power situation. As a result, it's basically a crap shoot whether it will work well or not.
Easy mode: find a triple radio mesh wifi system and get at least two nodes. Generally the LAN Jack on the satellite nodes will bridge to the LAN over WiFi. Just add a switch and use it normally. This will harm your overall speeds when connecting to the NAS from other wired LAN systems that are not on the same switch. I'm not sure if that's important. As long as your internet speed is less than half of your WiFi speed, you shouldn't really notice a difference.
Medium mode: buy MoCA adapters and use coax. Just be sure to get relatively new ones. They're generally all 1G minimum, but usually half duplex, so there's still sacrifice there, but MoCA is generally better than WiFi. The pinch is making sure you stop the MoCA signal from exiting your premise. You don't want to tap into someone else's MoCA network, nor have them tap into yours. There are cable filters that will accomplish this, or you can air gap the coax. I'm not sure how much control you have for the ingress/egress of your coax lines. You can yolo it and just hope for the best, but I can't recommend that.
Hard mode: do ethernet anyways. Usually in rentals, nobody can complain with holes in the walls the size you would get from nails to hand pictures, not much larger than a picture hanging nail, is a cup hook. What I did at my old place, which was a rental, was to buy large cup hooks, and put them every ~18" down the hallway, and load it with ethernet cables. I used adhesive cable runners to go down walls near doors and ran the cables under doors to get from room to room. I got lucky that two adjacent rooms shared a phone jack and I replaced the faceplate with a quad port Keystone faceplate on each side. One Keystone was wired to the phone line to keep existing functionality, the rest were connected to eachother though the wall as ethernet, and I just patched one side to the other (on one side was the core switch for my network). That was my experience, obviously your experience will be different. I used white ethernet to try to blend it in with the ceiling/walls which were off-white. In my situation, I was on DSL and used the phone jack in one of the bedrooms for my internet connection, that bedroom was used as an office and it neighbored my bedroom where I used the jack to jack connections through the wall to feed my TV and other stuff in the bedroom. The ethernet on the cup hooks went from the office to the living room where I put a second access point (first ap was on the office) and TV and other stuff. Inbetween the bedrooms and the living room was the kitchen and the wet wall was basically RF blocking, so I needed an access point on either side, so one in the office near the bedroom and bathroom, and one in the living room, provided plenty of coverage for the ~900sqft apartment we were renting. Most everything was on wired ethernet, and the WiFi was used mainly by laptops and cellphones.
I live by the philosophy of wired when you can, wireless when you have to. Mainly to save WiFi channels and bandwidth for devices that don't have an easy alternative option like mobile phones and portable computers.
I don't think you're in a bad spot OP, and any of these choices should be adequate for your needs, but that will vary depending on what speed internet you have, and how much speed you need for the LAN (to the NAS and between systems).