"And self-driving taxis mean you can use them for those journeys"

No.

You will have to call the taxi and wait for it to arrive, and (inevitably) you're going to have to wait a lot longer at peak times.

That is not the same as going any time you want.

Well okay. If you really feel that being able to take a trip to a less accessible location at a few seconds notice at peak times is vitally important to you, then you're still free to own your own self-driving car.

But I think most people would much rather wait a few minutes on those occasions and save their money.

(And FWIW, I think it could be fairly quick, since you don't have to pay a self-driving car to sit around in a small town in case someone needs it.)

Evidence is against it. We have cabs (also Uber, Lyft, etc.) now, but most people outside dense urban cores still choose to own their own car.

That's less true of the younger generation though.