Does it say, that then everybody has to live 15 minutes away from everything. It targets big polluted cities to make them a better living. Nobody says, you are disallowed to have more space for you if you want to and living in suburbs. That's exactly part of conspiracy theories.

I grew up and lived very long in Berlin. I rarely needed a car, never owned one there and I know many people who moved to Berlin and then got rid of their cars, as they didn't use it anymore. Berlin is not an example of a 15-minute-city but much better in a way of everything is close by, instead of having one center, it has several.

You can apply same for Zurich. Zurich is small in comparison to other european capitals (or capitals around the world in general). So in around 30 minutes walking you can be everywhere. Still a lot of cars there, but it is just so much more convenient, that you don't need it. But if you wanna use it, sure go ahead. And according to many rankings it is one of the best cities to live in (and I would agree with that).