I suspect the suburb issue is one of car centric US suburbs where you can't even get out of it without a car, rather than somewhere like the UK, where I effectively live in what is now a suburb of a larger city (if I drove there, it's about ten miles, through an entirely built up area), but that "suburb" is also a town that's been here since medieval times with it's own shops and workplaces and facilities.

Seems to me the issue is less about low density suburbs, and more about the fact that there's nothing there apart from rows and rows of identikit housing.