Streets have to access all buildings due to fire fighting reasons, unless you also plan to rearchitecture the firefighting infrastructure to use pipelines branching from a huge central fire extinction station.

Firefighting vehicle doesn't need parking space

It is obvious that a building requires road access. The issue of emergency services access has already been mentioned but there is also obviously the issue of deliveries, including large items like appliances and furniture.

I did mention the caveat that sometimes private transport (which includes bikes) may be inconvenient. That includes issues with parking space.

I'd argue that making private transport very impractical is not the same as making public transport "so good it becomes the first choice"... it's making private transport bad enough that it becomes more inconvenient than public transport...