Supposedly Nvidia has become a lot better on Linux lately. They finally dropped their weird framebuffer API or whatever (the one that was the reason for horrible Wayland compatibility and also caused a heated Linus Torvalds moment), and I think they even made their linux drivers open source.
They do support their driver yes, but it will never be as good as long as it’s proprietary. The open nvidia module isn’t ready and still backed by proprietary blobs.
Historically speaking, Nvidia was always the best for Linux. Nvidia's success history with Linux trace back to the 2004 with State-of-the-art 3d capabilities (albeit for arcade machines). At that time ATi radeon 3D capabilities for Linux were below sub-par.
The problem with Linux+Nvidia is that it was never "the Linux way"... but always the "Nvidia way".
The Linux way is... flexibility: it mean you can use whatever kind of Linux you want, and the drivers works straight out of the box (basically you need open source drivers). Instead Nvidia always pushed for fixed binary blob that required specific kernel and rigid environment.
The modern support for Linux by AMD is mostly "the Linux way", that's why the Linux community love AMD more than Nvidia.
In any case of hardware parity between Nvidia and AMD; Linux crowd will always prefer AMD, because AMD mean you can use any kind of Linux distro-thing and have an uncompromising gaming experience.
I've used a 3090 on Ubuntu and Arch without any issues for things like 3D rendering (Blender, Daz) and most of the Steam games I played without any issue. I was also able to run most of the AI models and tools.
AMD? Well, it works ok for games I guess, but it's a huge pile of shit other than that. Linux tards who pretend to care about "proprietary software!!!" on the one hand then talk about Proton/gaming performance in the other are nothing but hypocrites.