> Hard disagree here. Decentralization might reduce housing costs, but makes many other things more expensive. More roads to pave and maintain. Higher delivery costs. More time in the car to get to work, shopping, entertainment.

I think when people talk about decentralization they usually mean people moving from the big cities to existing less big cities. Those less big cities are usually built on the road and/or rail networks that are used to supply the big cities.

Decentralizing to such exiting smaller cities wouldn't necessarily be costly, especially if not done too fast.