Earlier quoted context omitted.
Saying that the macOS desktop is vastly inferior to Linux desktops is absolutely nuts. I've tried to get my relatives on Linux desktops so many times, just for it to go completely wrong a couple of weeks after and having to reinstall Windows. It's just not made for average (or below-average) users, so I don't see how it can be VASTLY inferior to something as easy and polished as macOS.
What are your relatives doing? If they're like 95% of computer users, they use them to check their email, their FB/IG/etc and browse the web. A Chromebook would suit their needs, but in my experience, so would a modern Linux installation + a browser. The biggest friction in my experience is UI differences, but that is solved by just mimicking Windows/macOS UI in KDE. Put buttons and components where they expect to fi…
I know Linux guys don't mind putting up with the Linux experience but if your family is trusting you as "the techie," you'd be doing them a huge favor by not making them put up with that stuff.