Exactly, the difference between unconnected wild areas (public access wise) and connected wild areas is massive. The landscape in large parts of the US is totally fenced in and splintered in a way that even if there is lots of public access it isn't effectively connected in a way that people can actually utilize it.

There are tons of hiking places that are walkable from most US city centers. Most US cities have large parks.

Unless European cities are smack in the middle of nature, I think they also have same issue.

It’s the US, you’re going to have to drive to it anyway because it’s 500 miles away.