They also create problems in terms of extra journeys as a private car will go from A to B, whereas a taxi goes from C to A to B to C.
It's quite amusing as people try to come up with more efficient use of cars and typically end up reinventing public transport (e.g. buses, trains etc).
Those extra journeys can be minimized with decent routing software. Even if it's as simple as ending up at B, then going directly to the nearest customer waiting for a ride.
And fwiw, if Tesla gets their robotaxi stuff working, their 22-passenger "robovan" is basically a bus anyway, just without a driver.
Bro just platoon the autonomous taxis into a convoy, give them separated lanes, and get rid of the rubber wheels and add steel wheels and steel lane guides for maximum efficiency. It's obviously new and revolutionary!