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.
If your friend ends up not liking the GNOME desktop environment because it's so radically different from the Windows UI, then maybe add the K in Ubuntu, I guess.
Well it very much does just work on mint.
Selinux could potentially screw people but it seems better than that one arch based "extremely optimised" (forgot name) distro which broke on my first install. And fedora base is quite solid.