Originally Posted by
Blind Wedjat
I think what has been missed is that T'Challa and Shuri have different approaches to technology, not that she's smarter than him or he isn't a genius level intellect.
T'Challa clearly sticks towards tradition. His suit (which he designed himself as stated in a Civil War deleted scene and in BP) is exactly like his fathers. Advanced, functional and classic. There's nothing wrong with the suit. It does its job and that's what matters. T'Challa at the end of the day is a king, a warrior and a protector. Functionality matters the most.
Shuri on the other hand, believes something can always be improved. She calls T'Challa's suit "old" even though it isn't (considering that Wakandan technology is still more advanced than the rest of Earth's) because it can't automatically put on a helmet. Keep in mind that what Shuri perceives as a flaw is never shown to be one, and the additions she gives the new suit are things T'Challa doesn't actually need. But that's her philosophy: there's always something to add. And she has the time to always think of something and always add something. T'Challa really doesn't.
But more importantly (and this is just my opinion anyway) T'Challa has always used his genius in the battlefield and less so in the laboratory, and he does that in his film. His extraction assault for Nakia in Nigeria is perfectly executed until she prevents him from attacking a child soldier. He leads the Korea mission, tells Okoye and Nakia what to do (and is the one that succeeds in capturing Klaue). He also is the one with the plan during the final battle, and he uses the mag-lev trains to exploit a flaw in Killmonger's suit.
With all of this considered I don't know how one can't say T'Challa isn't a genius. I want more of T'Challa outsmarting people and outfighting them with tactics. That has always been his shining quality as a genius. Priest never stated T'Challa invented his BP suit or gear (as far as I remember). It was how he used it that made him smart.