You’re misinformed, mostly.
NVIDIA had driver issues, incompatibility with gamescope (which was required for HDR) and a few instances of bugs, in WINE/proton, that caused performance problems in specific games/configurations.
Now, the driver issues for the mainline cards (the most common ones on Steam’s hardware survey) are about the same frequency as AMD hardware and we use Wayland’s native HDR, so gamescope isn’t a concern.
I’ve been using NVIDIA on Linux for 2 years now and I have never seen anything like a 30% performance reduction on any game, and I can also run local AI with acceleration.
As long as you’re using current hardware then you’re fine. If your graphics card was released 2 days ago, or is from the ‘00s then you may experience issues but otherwise NVIDIA cards work just fine.