Man I love urbanism (read some Jane Jacobs and Charles Marohn!) and talking about it.

First, the constant prediction of the end of cities is always overstated. Sure, maybe virtual reality will reach the point it meets our psychological need for other people, but overall you are only going to see a drop in the cities when there is economic decline or intentional centralized attempts to move people out like America did in the mid 1900s to push people into the suburbs. Both of those are likely to occur again in the US, but organically if a place is prospering its cities will be growing.

Sure, telecommuting might allow some people to live out in the jungle (and get their malaria shots and mosquito nets delivered by drones), but most people don't actually want that. I live a rural area and there is a constant stream of suburbanites moving out here for "more land"... but why do they need more land? They rarely use it for anything, and all it translates to is more time spent lawnmowing and more time spent in cars driving back to civilization for its amenities and socialization (and fighting in council meetings against farmers/loggers/etc). The only ones who do well are the homesteaders, makers, hunters, etc - those who actually need room for preferred activities. The rest just mistook why the suburbs suck and would have done better moving to a more sanely built environment.

Now as for the smart cities... they'll suck for the same reason all centrally planned cities suck. That's not how humans work. They need the complexity and chaos of a place built over time, with constant experimentation, unique successes and regular failures and all the adaptations and feedback loops that organic cities and towns provide. The smart cities will end up no different than China's ghost cities or Brazil's Brasilia (look! it looks like a bird! Not to anyone living in it of course, but to the planners sitting around with graph paper). That which is designed to a finished state can only stagnate or decline.

(Also, your bulldozing argument is a tad weak. American bulldozed tons of neighborhoods during its "slum clearance" phase to make room for expressways, sports stadiums, and housing projects. You can do it pretty cheaply if your a centralized authority - just declare all the buildings condemned and get the banks to redline the area.).