Fourth of July, kids sports that take place outside, etc. are all regular occurrences where people need to be able to easily go up onto a curb and park in the grass.
Seems like you’re grasping at straws to find weird edge cases that don’t at all preclude a mostly self driven future. I don’t think these cars will be made without steering wheels, or a mechanism to control the vehicle directly.
But I bet they get a report of how often you manually drive and if you cross a specified threshold your rate increases.
Edit:
Also why would you need to park on grass! Hop out of the car and it will park itself wherever in a nearby lot, or just drives around until you need it.
Your suggestion that all the cars should just e driving around waiting for you is fanciful, imagine something like a live music event with 100k people? Will there just be 100k cars circling the venue waiting for pick everyone up ?