We just recently had the DXVK 1.8 release for Direct3D 9/10/11 to Vulkan and now we also have the VKD3D-Proton 2.2 release landing as well. As the name suggests, this is the project especially made for the Steam Play Proton compatibility layer to work with newer games that use Direct3D 12.
According to the developer, the VKD3D-Proton 2.2 update is only a "maintenance release which fixes bugs and regressions" but as a big step it also "unblocks significant future feature development" so things shall continue to get exciting on it.
For the Windows games Death Stranding and Cyberpunk 2077 they have a workaround replaced with a "more correct and performant implementation" and there's also a workaround removed for Assassin's Creed Valhalla that's also no longer needed.
Seems like Cyberpunk 2077 should work better overall now too, as they mentioned their inability to reproduce a previous GPU hang. It's not clear if the game was fixed or if their work in VKD3D-Proton with a "memory allocation rewrite in 2.2" fixed it. Either way it seems to work okay now.
For other game specific improvements you can expect Horizon Zero Dawn to have better screen space reflections on water surfaces, DIRT 5 can get in game but not playable yet and stability on AMD Polaris cards should be improved in "certain titles".
On top of all that Variable Rate Shading tier 1 is supported now and for the big one — there's been a lot of background work added to support DirectX Raytracing but it's not supported just yet. The previously mentioned memory allocation rewrite has paved the way for more progress on it. As more and more games add in Ray Tracing or release with it, along with AMD and NVIDIA having capable hardware and Vulkan having an official Ray Tracing API - it's vital work.