Russo confirmed, that Shuri is the smartest character in MCU.

Right, because she built an iron armor in a cave that could defeat an entire group of terrorists. It wasn't her who in a lab full of resources built two random gauntlets to stand up against Killmonger and loose.

I don't think at all that Shuri is the smartest. She had to earn that, and she hasn't. If Tony Stark would have been raised in Wakanda, he would be 100 times more intelligent that Shuri is. Come on" Stark discovered how to time travel by using the Quantum Realm. He is the smartest.