GNU/Linux Gaming on Kbin

Spurred by the move to non-proprietary software I swapped out my Windows 11 for Ubuntu 22.04 LTS, and now 3 out of the 4 games I regularly play don't work well enough to play. I haven't checked games I only play occasionally, but I expect issues there too...

1. Path of Exile via Steam - Works perfectly, in fact maybe slightly better than Windows
2. Overwatch 2 via Lutris - Runs but with significant stuttering making it difficult to play
3. Diablo 4 via Lutris - Cannot run due to "Graphics Initialization failed" error
4. Melvor Idle via Steam - Runs but with minor stuttering and randomly breaks requiring complete re-install

I've Googled, and tried the most common solutions to these problems (like configuring Lutris to use VKD3D v2.8, running the script that Lutris provides with Overwatch, and add D4 to Steam and run from there) but no real positive changes.

For the most part, the rest of Ubuntu has been fine, but I don't want to be locked out of doing things I want to do on my own machine... Would appreciate any tips before I get too impatient and go back to Windows!

Thanks in advance.