Dad & I ...
... started MeDearOldMum out on a dumb terminal attached to Dad's AT&T 3B1 (so-called "UNIX PC"). A simple menuing system (sh and curses are your friends) worked for her for years. Then a couple of her friends got Windows 3.x boxen ... Dad & I just shrugged and went with the flow. What followed was several years of support hell, with MDOM constantly moaning about how awful modern computers were. Finally, I installed the variation of Slackware that I built for my Wife on Mum's machine. She still had the GUI "like her friends" (fvwm then, KDE now), but the complaints magically disappeared. She's been a Slacker for over 15 years, and support calls have been pretty much non existent.[0]
My sister uses Redmond and Cupertino and constantly gripes about them. For some reason she can't believe that Slack can work, simply because it's free. Mum & Dad have stopped trying to convince her otherwise. Me, I just gently remind her that I no longer support those products when she starts bitching about them. My brothers use Slack, but they roll out their own.
[0] I have to plug in new hardware for her ... but I'd have to do that regardless of OS. She's absolutely terrified of adding anything new by herself, and won't let Dad do it.