The first word that came to my mind after reading this question was “No one”. I don’t think that the abilities and powers possessed by Iron Man aka Tony Stark can be replaced by just any tech genius.
He is the one who pays for everything, he carried a nuke on his shoulder and went through a wormhole, his suit that he built himself is the just invincible (he has destroyed armed militants with the help of it), he dared to fight with Thanos who is more intelligent than him, and he is the creator of Jarvis –the epitome of Artificial Intelligence for all of us.
Talking of AI, I would say that replacing Tony Stark by any tech genius in Marvel
Cinematic Universe is as difficult (perhaps impossible) as replacing Elon Musk
in real life.
(Courtesy: India Today) Iron Man
is a natural leader, a futurist, and the one who is able to play multiple roles on the behalf of other Avengers if need be. Tech genius who was actually as genius as him was none other than Stark’s own father. So assumptions are the next tech genius to replace him would be the daughter of Tony Stark and Pepper Potts.
One more person who might be able to replace him can be Harley Keener whom we all have seen in Iron Man 3, but even he won’t be a perfect replacement. Yes he helped Iron Man
in the movie but even he can’t match him.