Intelligence, knowledge, understanding, wisdom, insight are different things and it's possible to have one or two of them in spades and be lacking in the others.
I'm not in the academic world any more, but I remember that it took great courage to say 'I don't understand that', it was safer to frown slightly and nod a lot instead of challenging the meaning of something that was complex to the point of obscurity.
The obscurity was taken as proof of its academic validity, so to complain about it was to place yourself outside the magic circle.
If you were, like me, someone who arrived at an academic job via a non-traditional route, and from a family background where nobody else had even been to uni, let alone taught in one, the pressure to conform was huge, so frowning and nodding slightly seemed like the best way to blend in...
I didn't blend in, I didn't get promoted, I wasn't one of the research stars, but I didn't mind because I actually liked interacting with students, unlike so many high-flying colleagues🙄