Getting my 7 year old set up on a Linux box, mostly for Minecraft... Distro recommendations?

Hey there! My son has finally "earned" a PC, and he'll be getting it for his birthday. I'm taking an old i7 Chromebox, upgrading the RAM and SSD, and boom that'll be his PC. I'm going to put Desktop Linux on it. My default go-to is to just install Ubuntu or Linux Mint on it, but I've admittedly been away from the Desktop Linux scene for a bit... What do you recommend? I don't need some kid-optimized distro, but I'd love the best out of box experience. Thanks!