Tony Stark is 100% the genius Elon wishes he was. He entered MIT at about 14, and graduated with multiple degrees at 17. While he didn't invent the arc reactor, he both miniaturized (As part of his origin story, when he created the first suit in a cave with a box of scraps.) and perfected it. If we go by MCU, he wasn't in charge of Stark Industries for a large chunk of the weapon development days, and after his kidnapping and Iron Man origin story, he had his company stop developing weapons, so now they're a tech conglomerate that does generic tech conglomerate things I guess.

He's also not real, so huge grain of salt.

EDIT: I want to make sure that before they reply that folks understand that "He's not real" is doing a LOT of lifting here. He (along with every other super-genius character like Bruce Banner and Reed Richards) doesn't cure cancer (he can), he doesn't give unlimited clean power to the planet (He could), he doesn't solve world hunger (he could), because he's not real. He's a character created to sell comic books to children, man-children, and connoisseurs of the medium (Me, clearly.) and as such can't solve any real problems with the world because then the comic would end as the we'd have world peace. He can absolutely do feats that don't result in world peace, like not being shitty like basically every other billionaire is, not dragging out a court battle against a union formation for years with high priced lawyers, and not stealing others work and claiming it as his own.