I live in Chicago and my family and our neighbors transport our children to school/stores/activities via bikes or feet. When the snow gets real bad we switch to sleds.

Anecdotally from observing my kids school I’d say that yuba bike linked is very popular. As are the Dutch bikes with the big front thing for hauling kids.

That of course relies on living in a place with infrastructure that enables it. Which is what Berlin is trying to build...