https://nymag.com/intelligencer/2017/06/lyft-reinvents-the-b...
The point is that we already have self-driving vehicles. You press a button on your phone and somebody drives you around. Whether it's a premium ride, a shared ride, or a bus is an orthogonal issue to whether the driver is human, which is a matter of cost.
The fact that it's a cost issue makes it look even worse and further out for driverless.
If there is demand for a shuttle along predetermined routes, it would already exist with a driver, and that's what Lyft Shuttle is if I understand correctly. I haven't seen it in SF or heard of anyone using it. It's definitely possible that they could figure out the product and it will become popular, but that has little to do with self-driving.
I see it the other way, they slot immediately and easily into already existing businesses and if the only difference is cost consumers are likely to swap over.
This also completely ignores the halo effects of these systems that vastly increase the economic output of the region. This is why it is often logical for the state to pay for the system, since the costs are centralized and the profits are distributed.