I think you don’t distinguish enough between professionals and capables.

Oh, but I do. The thing you're not seeing is that there's a difference between "can do something" and "willing to do something".

I am absolutely capable of filing my own taxes, did so in the past, but will never do it again: I hired a professional instead. She can do it faster than me, I can be sure she does it accurately, and according to the latest laws and regulations (so I don't have to keep myself up to date on those!). Not to mention that I save a ton of time, which I can translate into work, and I end up making more money in that time than the services of my accountant cost. Likewise, I also know how to change a tire. I also know that I never want to do that. If I have to, I will call a professional, because I can, and changing the tire myself is absolutely not necessary.

Similarly, both my parents are perfectly capable of maintaining their own systems (my Dad spent decades in IT, taught IT at a university, authored successful technical books on his area of expertise, etc; Mom programmed in DBase way back when), but they have no desire to do so. They have better things to do with their time.

It's not a question of "can", but a question of "want". A whole lot of people could maintain their operating systems. They absolutely do not want to, though. And if someone doesn't want to do something, the best way to help them is to make it possible for them to avoid doing the thing they don't want to do. In our particular case, that means maintaining their OS for them, for that helps a ton more than trying to force them to learn or do something they could, but viscerally hate.

You do not need to maintain your own operating system in order to use it. Rather than trying to force people into maintaining theirs, we should make it easier for friends & family to maintain it for them. That would be a far bigger win for everyone involved.