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.
It doesn't really matter for the average use though, most probably won't really notice the app opening times and most Windows users will not care about the backend being closed source, coming from an entirely closed source OS. I will tend to recommend stock Ubuntu or Mint/PopOS at most because those actually bring some things to the table while being Ubuntu based, not being Ubuntu but with a different DE
I've been quite enjoying Mint as well. Granted, it's been reeeal light use. But so far loving it. I've always enjoyed Debian distros. RHEL can kiss my butt. It was always frustrating to work with at work. I think Slackware was Debian? That was probably my first back in like 2004ish. Generally just works™