Mainstream full self driving would just create massive traffic and gridlock - pointless in the end. The induced demand would outweigh the benefits. States are better off acknowledging that sprawling car dependent cities are not sustainable. High frequency busses in the interim with rail transit is the real solution. Current self driving technology plus some key infrastructure changes with dedicated bus lanes and prio…
One of the killer feature I expect to see in the future when we have FSD is that cities will take direct control of traffic in a central way. If cars can be distributed evenly over all roads with each driver getting an average distance/time-to-arrival the overall speed would significant increase, with car owners loosing the control to pick the shortest route in order to be allowed to use the roads in the city.
Centrally controlled FSD cars would also allow for much faster intersection since all cars could accelerate and break simultaneous. Both would require quite tight control and coordination that only computer controlled cars could do.