We've had 15 minute cities centuries before the USA became the USA.

Cars are responsible for destroying them in the first place, because why open a small shop when people can just drive 20 minutes to get to your mega warehouse sized store instead.

The only thing restricting in 15 minute cities is that some places contemplated making the roads toll roads for outsiders. Which isn't all that different than every fucking highway having a lane permanently allocated to toll service and nearly every destination charging $12/h for parking and requires a credit card to even get to the parking lot.

The 15 minute cities are great for poorer people, and solves most transportation problems that keep them in poverty. No beater cars to get repaired every week. No expensive gas. No stupidly long bus rides. Much better for the environment. Here my windows get covered in soot from trucks and I'm not even on a main road, while in Montréal the air was mostly fresh because few are dumb enough to bring a diesel truck in the city.

The point of 15 minute cities isn't to take your car away. It's that you shouldn't feel the need for a car in the first place, because you just don't need one. The traffic and pollution problem solves itself.