In August 2021 Bethesda released a new, enhanced version of Quake 1 with soundtrack, new graphics, new mission packs, achievements, multiplayer cross-platform with console peasants, and so on. It uses the KEX engine that was designed to emulate other game engines, and thus port old games to new systems. It doesn't support Linux, of course, but it runs fine with Proton.
By default KEX uses Vulkan rendering. If you have trouble with Vulkan, find the config file at steam/steamapps/compatdata/2310/pfx/drive\_c/users/steamuser/Saved Games/Nightdive Studios/Quake/kexengine.cfg, and change r\_rhirenderfamily. The supported values are vulkan, opengl, d3d11. By default Proton uses DXVK to translate D3D11 to Vulkan, so if you really have to turn off Vulkan, you can either select OpenGL, or instruct Proton to use Wined3d for D3D11. To do that, open the game properties window, and on the General tab set the Launch Options to PROTON\_USE\_WINED3D=1 %command%. Note that Wined3d is not officially supported by Proton.