My non-tech literate aunt has been running her Ebay business from a laptop running Fedora with unattended upgrades for 3 years now. She manages her expenses in Libreoffice calc and accesses everything else through Chrome and prints labels on an old USB HP printer. I don't think she's even noticed I switched her over from Windows 10 when her machine was getting slow.

My Dad's laptop is also on Fedora (though he mainly just uses an Android tablet these days) and I intend to install it on my Grandma's PC when Windows 10 stops being supported. So for the people who'd be happy with something like a Chromebook, which is a good chunk of older folks, it's perfect and I can easily provide support.

That being said if I had to deal with helping kids who wanted to game and use Bluetooth bits and pieces surrounded by RGB crap then yea outside of a few well supported options it could be a nightmare depending on what they've got.