Yes and no. I have an AMD card in my desktop and a laptop with a slightly more recent nVidia card. AMD is better for the display drivers IMO, so if you’re looking to get 3D acceleration and just play some games they are the way to go. AMD’s drivers are typically signed with the kernel and makes SecureBoot easier to setup, plus they play nicer with Wayland. Personally I prefer supporting the company putting out upstream Linux drivers. But if you’re looking to do GPUGPU tasks (like darktable’s OpenCL support) things get muddier.
AMD’s OpenCL/GPGPU support is still really spotty along with their video decoder/encoder support on Linux. I get much better performance out of NVEC on my laptop than VAAPI on my desktop with OBS and Kdenlive and the cards aren’t that far apart in that respect. ROCm is still hit or miss with different applications, AMDGPU Pro (AMD’s proprietary driver, not to be confused with the amdgpu open source kernel driver) support is really very distribution specific and requires legwork on non-REHL/Ubuntu distros to get working. I’m using the AMDGPU Pro OpenCL drivers right now and there are bugs with the latest mesa versions on Fedora because it’s unsupported.
If you’re using a distro that has the nVidia drivers available in a repo, don’t need Wayland right now (aka don’t have a convertible/tablet or something with multitouch) and want the most trouble free GPGPU support nVidia is the way to go still.
That being said right now it seems the best graphics card is the one that you have already. I don’t envy anyone trying to buy one in 2021.