While I can't speak first hand for AMD as I've not owned an AMD/ATI card in decades I do know that AMD and Valve have dedicated Linux driver deveopers directly contributing them to the kernel and have heard nothing but good things (taken with a grain of salt because fanboys will fanboy).
AMD drivers are open source but that alone doesn't make them "work better" than the Nvidia drivers.
Funny thing is I sometimes use steam remote play to access my linux desktop since it's faster and has very little lag compared to VNC. I simply add nautilus to steam game library so I can launch it remotely via steam link, then press "super/⌘" key to access the desktop.
I am not gamer anymore. I've had NVIDIA GPU, binary drivers were not pleasant experience, so bad that I've switched to Intel GPU. Today open source AMD GPU driver is a clear path forward, and it would improve with each release.