Generally speaking amd is favored over nvidia on linux because it's driver lives in the kernel (more free), better wayland support (this is changing tho) and not having to install a driver manually or an installing a restricted driver from the package manager. I've been running my 6900xt for a couple of year and it's been great. The only downside of amd is if you need/want some of the nvidia tech like rtx and cuda. Here are some older benchmarks from when the 7900 xt was coming out https://www.phoronix.com/review/rx7900xt-rx7900xtx-linux