I have literally biked many of the routes you’re discussing here. I live in Sacramento and regularly visit the Bay Area without driving. Actually, that’s already the most convenient way to do so. But that’s a fun outing, not practical urban transit. Practical urban transit takes place within or to adjacent neighborhoods. That’s the whole point. Once you reach a certain density of amenities, car infrastructure and travel becomes totally impractical. This density is well below American suburbs, which is why our cities are all clogged with traffic and people are being flattened left and right.
For occasional longer distance trips you can rent a car or take a train. We’re not talking about inter-city travel here. The point is, like the above video, people, especially children should have the ability to safely navigate their neighborhoods. And this is totally achievable in the US.