For anyone with an HD 7000 / R9 200-era card or an old GCN APU sitting in a drawer: the move to amdgpu as the default for GCN 1.0/1.1 means you get RADV Vulkan, so DXVK/Proton games that simply wouldn't start on the old radeon driver now have a chance. If you're on an older kernel or a distro that still binds radeon, lspci -k shows which kernel driver the card is actually using.

Nice to see the talk also cover how he moved from Mesa into kernel work, that part is useful for anyone thinking about contributing.