I can understand why it was the case in Europe, where you had to quickly replace all the buildings and housing lost due to the war, but why here?
This site has had a number of threads about global trends in architecture, and why they seem to be converging.
https://culturaltutor.com/the-library/architecture
Elites choose building designs and architectural styles. The design choices represent what is aspirational for those elites.
When you have public buildings which are huge, ugly and demoralizing, it reflects, in my view, the aspirational agenda of the elites to reduce the populations they rule to insignificant scale compared to elite created monstrous inhuman structures.