The farther the car goes to park, the longer the wait for it to pick you up on demand. Not to mention, traveling a few blocks rarely saves much on parking in densely populated areas.

It can travel way further than "a few blocks" and I'd guess most trips are not so unexpected that it's impossible to accept a delay of 30 minutes or maybe even longer.

If your parking spot isn't included as part of the building where you live, then you're going to have to either buy some more property (however small or far away) to keep your car, or pay someone to let you park your car on theirs.

Yes, agreed, but if you live in a major city that's already the case (or you drive around for an hour looking for a space, something the self-driving car could also do).

Right. And so my point is the expense and inconvenience of parking in cities is incentive for you to either (a) not buy a car, and instead use an on-demand (self-driving) rideshare service, or (b) buy a car, and recoup costs at little inconvenience by putting it into a self-driving rideshare pool.

The end result is fewer cars owned by fewer people, but utilized much more fully, so the cars that do exist in cities spend more of their time driving and in-service, rather than sitting parked and empty for 98% of their lifetimes.

But a self-driving car that can either find street parking or else drive to some suburban lot makes that incentive much weaker, not stronger?

A service will be able to keep cars near you, and will have sufficiently higher utilisation of their cars to be willing to pay more for parking spots. Your waiting time to get a taxi service will likely drop substantially at the same time as your waiting time to get picked up by a car you own is likely to go up.

As someone who doesn't own a car, the only potential appeal to me of owning a car is shorter waits and predictability (always there). If the predictabiity and waits drop for rental services, my reasons for considering buying a car would rapidly drop. If the waits to use a car I own go up, my reasons for considering buying one would drop further.

As someone who doesn't own a car I don't think you have that much insight into the mindset of people who own a car.

You're assuming I've lived in a car free household all my life.