MacOS (which is what it's called now, OS X name got retired) will annoy you, changes annoy people, but if you buy an Apple product it'll actually work for quite a few years. Not 15, unless you're unusual, they're not supported that long. If you want your software or hardware accessories to be supported forever, they won't be. If you have really opinionated positions on how something will function forever, you'll be disappointed.

But out of the box it works. Hard crashes are very rare. User hostile things like forced updates don't happen.

The worst things are much much less likely to happen than with hardware that runs Windows, and if something happens the tech support at Apple stores is pretty good. If you want a good Windows machine you have to do extensive research to figure out how not to get crap, and you still end up wrong sometimes. If your grandma wants a computer, you can just tell her to go to an Apple store and get whatever she wants and it'll work.