I found it funny that I've been tinkering with mods and settings, unsuccessfully trying to get the game to run at all on Windows, but then it started up right away on Epic Games Store through Lutris. Now I just gotta figure out how to cap the frame rate. e: found an fps limiter on nexus mods, now everything works perfectly!
Previously I had a similar experience where Far Cry 1 wouldn't run on any Windows newer than XP, but worked perfectly on Linux.
I think it's possible to use dxvk on Windows too. That could be used as a workaround.
I was able to get it running great on Windows with an AMD GPU by following this guide EXACTLY: https://vivanewvegas.moddinglinked.com/ Honestly though, this is way too much work to go through just to get the game running and stable, I think just the mandatory parts of that guide took me almost 2 hours to go through. (Maybe that isn't actually very long to spend installing mods? idk I typically never mod games heavily)
I really need to try switching to Linux again soon.