> Your parked car is adding to congestion. It takes up space that could otherwise be used by humans.

But that's not what congestion means.

It's adding indirectly, more space taken by parking lots means that you have to spread further, which begets the need for more cars

Less parking spaces > denser enviroments > more walking(Or other more compact forms of transport) > less cars (To an extent) > less congestion

The US has multiple (smaller) countries worth of parking space

I'm immediately suspicious of any chain that links "denser environments" to "less congestion", since everywhere I've ever been, the densest environments have the most congestion.

It's a bit like adding extra lanes, to some degree, demand expands to meet capacity (But I mantain that in this case the net effect is possitive)

There would be less space to be congested by fewer vehicles, but in this context, less congestion also means fewer people experience the congestion directly (because it also works to disincentivize car usage), but those affected have it the same or worse.

I wouldn't take my car to a large city center if I can at all avoid it, which seems to be the common reaction. These people are "transparent" to the congestion—they don't add to it and (mostly) aren't affected by it.

On the same idea, I think the densest enviroments are a bad comparisson There's a noticeable middle ground between US Style Sprawl and say, Tokyo

But the alternative to Tokyo isn't Tokyo but with 20 million cars, it just stops being Tokyo

Density accounts for situations that expansion can't

So optimal would be to get entirely rid of private and single user vehicles likes taxis. Thus density could be maximised.

If it’s parked on the street, that is taking up a lane that could be carrying traffic. (And in some cities it’s common for parallel street parking to turn into a lane from 4-8 PM or similar)

Robo-taxis can pack significantly more densely into a dedicated parking space than regular cars. Snout to butt and no room side to side, as there's no need for maneuvering. A robo-taxi parking lot just becomes a dense FIFO queue.