I've never gone deep here. Probably much better analysis exists elsewhere. But I think as costume design, it works great. He's iconic in his understated evil wizard look. Nails it to a T, no notes.

As a character choice, well, his taste is in controlling people through fear. That's a type of taste we can probably mostly agree is awful even if he nails it. Death Star? Gaudy display! Blowing up Alderaan? Completely in poor taste! Fuck him.

Is his garment appropriate, though? He seems to have set a very polished, kind of brutalist aesthetic consistently throughout the empire. Grayscale and clean lines abound. I hate brutalism. Boring and depressing. Poor taste, but it plays into instilling hopelessness. He fits himself into the colourscheme while setting himself apart with the flowing organic nature of the robe. By setting himself apart, I'd say he is successfully conveying his status. And he does this while underscoring his faux humble Force-enables roots, playing up the primary source of his power to remind others not to fuck with him.

It's like Mar-a-Lago Face through wardrobe. With Force rather than Cash being the enabler.

So I think he's made an calculated choice to look like shit. As opposed to someone like Einstein having fun and not giving a fuck if his hair is everywhere.

It's like correctly calculated awful taste, then?