As for those pictures from Sarajevo... well, that's what I don't "get".
The commies turned to brutalism as, basically, a way to cheaply house millions of workers. They weren't supposed to be beautiful, and sometimes not even nice to live in.
They had a problem like, basically, that by 1917 Petrograd's industry had exploded and the city hadn't kept up. There were a lot of apartments where as much as 16 workers were not as much room mates, as hot-bunking. Moskow wasn't that far behind. Stalin's forced industrialization caused a very sharp urbanization too, which just made the problem even worse, and spread it to other cities too. They had to pretty much move a hundred million peasants into cities, and fast.
The other Eastern Bloc countries followed similar patterns, though to different extents. Some were already more urban.
And the fact that the economy was crap, also didn't help.
So they turned to, basically, cheap, mass-produced, blocks of flats. Aesthetics were not a goal, housing the most people with the least cost was.
But that's kinda the point. Those were not supposed to be artsy buildings or anything.
And when they wanted something nice, like the villas of the elites, they didn't go brutalist about those.
Basically those buildings in Sarajevo have an excuse.
Now witness the kinda similar phenomenon in the West. Some of those brutalist abominations actually were supposed to be avangarde and artistic, and they hired some celebrity architect to... make a misshapen concrete box.
W.T.H.?