One shouldn't forget that suburbisation was a Cold War move - a very effective one and something Soviet Union could not even remotely afford to follow. Quite likely that it eventually prevented nuclear war by making it clearly unwinnable for the Soviets.
It also prevented firestorms by making buildings less dense - there wasn't enough density of combustible material. And made it possible for every family (middle class family - which in 1950s timeframe, meant qualified industrial workers, engineers, and the military - those a nation would need most in case of major war) to have a basement to escape fallout. Downtowns have been left to the part of population deemed useless and dispensable.
In Soviet Union, that kind of the most important members of society, lived in apartment blocks in city centers. And because Soviet Union did not have, and could not afford, mass automobilisation, they were stuck with that.
