My experience is that universally my linux gamer friends who own AMD products have worse experiences than I do - they are absolutely usable, but not worth buying at all if your primary purpose for owning a GPU is gaming.
> Black screens & hard freezes are nonexistent. Gaming performance on the Steam Deck and APU is reasonable for the hardware. Proton works better for me with AMD than NVIDIA (which makes sense, after all Valve’s development of it is aimed at the steam deck primarily).
Most likely you are playing games that Valve has already deployed patches/hacks for. Go off the beaten path from Steam and the proton runtime and you will find quickly that AMD is severely buggy.
Black screening is especially common with vega dgpus, can't say if it extends to the igpus are not but if you google 'vega black screen bug linux' you will find hundreds of reddit posts and bug reports about this going back to 2018.