I'm going to reframe the question as "Are computers good for someone tech illiterate?"

I think the answer is "yes, if you have someone that can help you".

The problem with proprietary systems like Windows or OS X is that that "someone" is a large corporation. And, in fairness, they generally do a good job of looking after tech illiterate people. They ensure that their users don't have to worry about how to do updates, or figure out what browser they should be using, or what have you.

But (and it's a big but) they don't actually care about you. Their interest making sure you have a good experience ends at a dollar sign. If they think what's best for you is to show you ads and spy on you, that's what they'll do. And you're in a tricky position with them because you kind of have to trust them.

So with Linux you don't have a corporation looking after you. You do have a community (like this one) to some degree, but there's a limit to how much we can help you. We're not there on your computer with you (thankfully, for your privacy's sake), so to a large degree, you are kind of on your own.

But Linux actually works very well if you have a trusted friend/partner/child/sibling/whoever who can help you out now and then. If you've got someone to help you out with it, Linux can actually work very very well for tech illiterate people. The general experience of browsing around, editing documents, editing photos, etc., works very much the same way as it does on Windows or OS X. You will probably be able to do all that without help.

But you might not know which software is best for editing photos. Or you might need help with a specific task (like getting a printer set up) and having someone to fall back on will give you much better experience.