Valve amended the Steam survey for December 2025 - Linux actually hit another all-time high
(www.gamingonlinux.com)
if your friend is already a basic knowledgeable user and can partition their drives, tell them to just go install xubuntu and try it out. no need to worry about the multiple partition options during install, just do a basic single partition install and try to do a few common tasks. see how it goes and then wipe it and reinstall later.
edit: it took me maybe 3 hours total to install Linux on two computers, including downloading and creating the installation media and waiting for it to finish running the installation etc. and the installs themselves were problem-free, all of my issues were related to other things like trying to sort out SSH and remote desktop viewing access.