There are actually quite a few factors that fall into GPU, fps and the pieces.
I have found that running Gnome and amdgpu will provide the best FPS.
Running amdgpu-pro and the RX 550 and getting 52 fps is really good and shows heavy improvement. The Linux side of things is certainly not there biggest concern and we will always be a second thought when it comes to this.
There is certainly more room for improvement and always will be. What needs to happen is us folks that use linux is visibility. As a community we need to be visible and loud (IN A GOOD WAY)