> The customer might be able to do it themselves

Have you ever paid for software? I have, many times, for things I could build myself

Building it yourself as a business means you need to staff people, taking them away from other work. You need to maintain it.

Run even conservative numbers for it and you'll see it's pretty damn expensive if humans need to be involved. It's not the norm that that's going to be good ROI

No matter how good these tools get, they can't read your mind. It takes real work to get something production ready and polished out of them