First of all, 350MB is a drop in a bucket. But what's more important is performance, because it affects things like power consumption, carbon emissions, etc. I'd rather see Slack "eating" one gig of RAM and running smoothly on a single E core below boost clocks with pretty much zero CPU use. That's the whole point of having fast memory - so you can cache and pre-render as much as possible and leave it rest statically in memory.