You don't see any difference between banning cars and simply putting the parking spaces in a garage instead of on the street? The difference seems pretty stark to me — one implies that people cannot drive there and the other implies that people will drive there.

No, my point about the garage is that you could easily ban parking in the main pedestrian area (Main Street, the waterfront, and the circle in Annapolis) because most people already park in a garage outside the main pedestrian zone. Many plans for downtown car bans contemplate parking outside the car free zone.

In the US, cars are privileged forms of transport.

Just as we have shopping malls with outlying parking surrounding a pedestrian only area, you can engineer urban cores with appropriate pedestrian infrastructure, that are served with a network of transport modes outside of the core, including transit and garages.