Valve's proton and VKD3D basically covers all of that. The only games that I have any trouble running on my fedora/amd system are those that use invasive anti-cheat.

There are directX to vulkan translation layers such as https://github.com/doitsujin/dxvk for up to dx11. For dx12 specifically, you have vkd3d: https://gitlab.winehq.org/wine/vkd3d/-/wikis/home

isn't VKD3D good enough?

To the downvoters: I am well aware that Linux can run modern games. In fact my gaming rig is a KDE Neon 6.2 install with all latest mesa, amdgpu, etc. I play the latest dx12 games just fine on it.

But the original point wasn't whether Linux could, but whether it's different from Windows.

And as someone who compiles DXVK from git: dx12 won't work out of the box; it is different from Windows. Not particularly difficult, but different...