> Brutalism expressing domination over people - I've always seen it more as expressing function in form, which would be the opposite

It expresses the architect's idea of function, which may or may not have anything to do with the actual users. However, whenever the actual users of a building complain about the poor UX (noise, leaks, discomfort difficulty finding things in the layout) or their feeling of unhappiness induced by the blankness, it's traditional for Modernists to tell the public and users that they're wrong. It's that elitism which more than anything else characterises the failures of Modernism, of which Brutalism is a part.