Its funny how mass transit was once seen as a way out of the crisis of too many city horse carriages and all the manure they produce. Metro and rail was simply considered the natural solution, which combined with denser living space allowed for labor intensive industries to sprout up around cities. But then came the horseless carriage and suburbian sprawl became a thing and now we have too much of that. Too much hardened soil and flooding is becoming a much bigger problem, animal and insect populations wither, road networks have upkeep, transport and storage costs make everything imperceptably more expensive. In my scifi fantasy future vertical farming will become a thing which should allow a major shrinking of hinterlands around dense population areas, though preferably not replaced with suburbia. Maybe we could go live in the clouds too.