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.
I strongly reccomend Zorin OS. I was in his exact shoes when I decided to switch to Linux and for very similar reasons. It feels pretty similar to Windows 7 IMHO, and I like its default dynamic background that changes throughout the day. Steam games run great on it btw.
The other reason I reccomend Zorin is that it is aimed at windows users and Mac users. There's an "app store" that is in fact a software manager, most windows apps run pretty well (although I reccomend using Bottles for that) and the layout is designed to feel similar to Windows. All the fun Linux stuff is still right there for you to use, it's just slightly out of sight so it doesn't overwhelm you at the beginning.