30 minutes before the show is over, you order the car to wait in the "no stopping" zone in front of the theater for easy access. You exit the theater and find your car is tangled in a mess of traffic that takes 45 minutes to clear as most of the cars are double-parked and blocking traffic, waiting for their owners. For the duration of the show, no useful traffic has been able to move for a mile in any direction, as empty cars are just idling around and are content to wait, fully stopped.
Tragedy of the commons.
I think one solution would be to charge for each minute you are in a congested area to avoid having a whole bunch of empty cars clogging the streets.
With AVs, this limit no longer exists, and people will start using AVs for runs that currently are prohibitively expensive with care that require drivers.