It's a collection yes, much like the national epic of my country, Finland. Those epics are still considered to be written by the person who actually... wrote them.
It doesn't matter though whether Homer is a single person or many, real or fictional. What matters is that we've not lost the context of the story.
In your argument, it's more like a 1000 years from now people would consider George Lucas to be the creator of the Mandalorian. It wouldn't be correct, but it wouldn't be too far off the mark, and most importantly, nothing important to the context of "what is a light saber" would have been lost.
The point is that writing hadn't even existed too long by the point that we managed to preserve stories to last until modern times.
Our current technology is undeniably far superior, and there are dedicated institutions and people who preserve important information, especially culture. Star Wars is undeniably a part of that.
There is pretty much no situation in which we'd lose the context of what a light saber is, except pretty much the destruction of the entire world, all media wiped out somehow (despite that meaning the destruction of literal nuclear bunkers) and the extinction of anyone who knows about Star Wars.
The scale of destruction would need to be such that humanity itself wouldn't survive it.
It's more than likely that Star Wars will outlive our species.