Aside from the general "not gonna work" thing, I get so puzzled about the faith people have in the idea that when self-driving cars exist all we will need are robo-taxis and then things like parking requirements can just disappear.
First, peak commute time doesn't go away. Sure most cars sit there doing nothing most of the time, but a lot of people need them between 6-9 and 4-7 (or so) every weekday. Got match that demand somehow.
Second, the idea that people can just summon a car so we don't need massive amounts of parking in front of every location ignores a lot of things. All those empty cars being summoned to pick up drivers are going to add a lot of congestion to roads, which to some degree will become mobile parking lots (perhaps literally, with enough congestion). People used to walking out the door and into their own car really really hate waiting. 5 minute wait to pick you up at Target while your kid is screaming? Sure. Also, too, in general "pick up lines" are going to be a big source of congestion, as anyone who has ever made a school run knows.
Third, kids again. People use their cars to store all kinds of things, including of course car seats for the kids. Also bottles of water. And blankets and binkies and random things to entertain them and... Also, not just kids, people in general use their cars to store lots of things that might be useful to them.
None of this says, "oh sorry self-driving cars won't work" (they won't, but that's a different issue). They just won't provide the fantasy urban transformation and comfort/convenience enhancement that people imagine. The things still gotta park somewhere, peak demand at commute time isn't going to go away, and for good reasons people who regularly use cars will want their own car. Maybe it'll be self-driving, but it won't be a robotaxi.