I do acknowledge that humans are social animals and there are benefits to face to face interactions, but these come at enormous costs. These costs aren't merely financial as so many people emphasize, but material. The material cost of cities on our planet is quite high. The amount of concrete, metal, glass, and other materials is quite large. With decentralization we would have an increased use of roads for logistical concerns, and we'd have an increased sprawl issue, but there'd be so much less traffic overall I think we'd have a net win on air quality. The next issue to tackle would be expressly limiting sprawl, and I have no idea how that'd be done.
EDIT: Comments have been that this would decrease production. this is entirely accurate. Most items today aren't made to last and we have become accustomed to hyperconsumption of low quality stuff. No doubt. Scale has alternatively raised the standard of living the poorest among us by insane amounts. There is severe good and severe bad that have accompanied this remarkable economic boom of the last 100 years. The thought that I really have regarding this is that Amazon has made it possible to distribute insane amounts of stuff to a distributed buying public and there must be a way to manufacture in the same way. I am not a logistics person, and I could be entirely wrong (I probably am), but it's a dream and not a proposal.