You should check proton logs. Add the following to launch options: ‘PROTON_LOG=1 %command%’. Then launch the game, you should see log file appear in your home directory.

Also, what’s your graphics card?

There’s also RetroArch, though can be a little pain to setup.

Vast majority of games work just fine on linux, can’t say for launchbox (looks like just a game launcher, if so, you can use Steam Big Picture mode, even for non-steam games, emulators etc.)

Visual Studio does not work, but if you’re a C# developer, there are cross-platform alternatives like VSCode and Rider.

Note: probably don’t use Ubuntu if you’re trying to escape a corproation dictacting how to use your computer though