Demand-responsive transport (DRT) has been tried a bunch of times in all sorts of different environments and pretty much never lives up to the promise. Predictability is really important and ridership drops as soon as users start having to plan too far ahead, which in the past has been essential to DRT routing.

Autonomy could improve responsiveness to demand but you still run into other issues. DRT usually won't be able to take advantage of things proven to make buses faster and more consistent (bus lanes, reducing stop count, transit priority signals). Futher, consistency and response times gained by dynamic routing can easily be overshadowed by increased variability in trip time as the route adjusts to add new passengers or make out of the way drop-offs.

Those busses still need designated spots to stop at. They can't be stopping in the middle of a street

Autonomy isn’t necessary, but aside from cost there’s nothing stopping a city from operating a bus more like a shared Uber ride. Having fixed stops at fixed times is fairly primitive. They would be smaller shuttles.

Waymo is worth nothing if there’s congestion. That’s the problem public transportation solves, not lack of connectivity

Wait until you're waiting in the wind and snow with a toddler, and you'll prefer a bus shelter.