2024 is the Year of Linux on the Desktop, at least for my boyfriend. He's running Windows 7 right now, so I'll be switching him to Ubuntu in a few days. Ubuntu was chosen because Proton is officially supported in Ubuntu.
You should try plain Debian and KDE Plasma (the desktop it's one of the options of the shelf, you just pick it with the installer). I have been doing that and it's great, even with old hardware. Ubuntu is way too much bloated. And of course proton works like magic.