If they are competent with computers, they can probably figure out Ubuntu and maintain it theirself.
I left Ubuntu for systems I manage because I’m not smart enough or willing to invest time learning snaps, and snaps kept breaking Firefox updates and generally made Firefox unusable. Since I’ve been around a while, I found it was just easier to migrate my fleet to Debian and set it to look like Ubuntu with the dock on the left. This has been fine since 2022.
If it’s something you would be partially managing, and they didn’t like Mint, have them try Pop!_OS.
If it’s a super simple, low maintenance desktop, just go Fedora Silverblue and it will stay solid and up to date until the hardware dies.