The distro doesn’t matter, the Desktop Environment does.
If they are used to MacOS and want something simple and “out of the way”, go with Gnome.
If they are used to Windows, go with KDE.
Fedora is probably the most straightforward to install and manage right now. You won’t need to “lock down” anything if you don’t give them sudo credentials.and just a regular user account.

























Having been in the app store development community for a decade, this isn’t honestly the WORST thing. So much malware gets pushed now it’s a fucking gha-tto. This isn’t the worst thing to combat, though I believe there should be a FREE tier for Open Source or otherwise community-driven apps to be released on with zero barriers - AGAIN, oenisn game sort of verification which could be cheap, reliable and FREE.