Interesting! I used arch for about 2 years on my gaming rig and it worked fine but I was worried if he went with something based on Arch that he would eventually run into issues due to not properly maintaining it (avoiding partial upgrades for example). But I’m probably overthinking it. If he sticks to a GUI for installing and updating packages and avoid messing with the terminal initially it should be fine.
I will add EndeavourOS to a small list of recommendations (rolling vs point release) so he can decide for himself.