The rest of the world is building subways like crazy. The U.S. has pretty much given up
(www.fastcompany.com)
I mean, we've got the rails. So I am not saying it's like we don't have rails. But more so I mean the urban density just isn't there (which is what you're talking about with the suburbs). But also that usually comes with industry, and there's so much space in America that just doesn't pull the level of industry and even if there's "cities" it basically just ends up having cities that look like burbs or like they're from the 70s (because I think a lot of architecture is from there or the 80s). And I know Japan has the bullet train, but it's way smaller than here. Idk what's going on in China, so I can't talk there. But I will also say that in America a lot of public transit is intentionally used to keep group a away from group b. So extending that access isn't seen as desireable.