The suburb hate bandwagon on here has gotten way out of hand. They are not inherently unsustainable and it is not a "waste" to spend a bit more resources to make a space that's nicer to live in. Not everybody wants to have to walk everywhere/take public transit and live like a sardine in a can getting accosted for spare change all day. And are you saying you'd really let a kid "explore" in a city? You're not even particularly safe in a "walkable city" as a lone adult if you go down the wrong street or you're not paying attention.
https://en.wikipedia.org/wiki/The_Death_and_Life_of_Great_Am...
I noticed that the author mentions that a busier city street is safer from violent crime but doesn't acknowledge that very busy streets are also havens for pickpockets, whereas you generally get it both ways on mostly-vacant-except-cars streets in lower density areas with little to no violent crime.
AR/VR will enable more spatially interactive technologies as well. Pokemon Go was a fad but I think it heralds a yet-to-come wave.