From what I can tell, gaming with an nvidia card on Linux is still rough. Is that incorrect?

Somewhat. There's still a ~20% ish performance impact for DX12 titles on Nvidia, but on any newer/recent card it basically just brute forces it and ends up being fine unless you are an FPS chaser and have an issue with getting, say, 140 FPS instead of 168 FPS. That'll matter if you play competitive PvP games, but otherwise you probably won't notice (depending on the game)

It depends on your card I think. I can say that with a 3080 Ti and now a 5090 I have no issue playing almost all the games on steam on Fedora 44, event a lot of games not explicitly compatible. I’ve been using Linux only for probably a year now and I don’t see a good reason to go back to Windows for gaming myself.