Clark's the son of the most talented scientist on a world full of highly intelligent, advanced people (who in many versions, liked to tinker with genetics and made sure everyone had a role and place, often associated with what their House was known for). His raw IQ should make most humans feel entirely inadequate. Lex and Mr. Terrific and a few other big brains should rival or surpass him, but.....just to put it into perspective; Power Girl learned, in Kryptonian high school, stuff that it took Michael Holt (with all his different degrees) months of research to figure out. They're a smart people, Kryptonians. Sure, Terrific had to do the work himself while PG didn't, but I didn't understand the theory of relativity in high school despite not having to do the fundamental discovery work.
But two things add really interesting wrinkles to this.
First; Clark definitely dips his toe into the hard sciences of physics, engineering, chemistry, etc., but they're not where his heart is. He's a sociologist and philosopher. He knows his way around a lab, but he finds the problems of people more complex, compelling, and challenging than he does some tricky bit of research in the Fortress.
Secondly, his education. Clark has a wildly uneven educational background. Most of what he knows, he learned on earth from earthlings. He learned the same stuff we did in school, and while he certainly did his own independent studies, he'd still be limited by what *we* know. But he also has these experiences with technology/knowledge well beyond our own; stuff in the Fortress, alien invaders, the 31st century, etc. That stuff opens him up to all kinds of things earthlings haven't even theorized yet. Clark has a relatively grounded base of education (which negates a lot of his IQ in a lot of ways), offset by these narrow but deep dives into all manner of odd bits and pieces of scientific inquiry.
Clark's the kind of guy who might know how to build a time sphere, because he helped Brainy repair one in the 31st century, but wouldn't know how to build something far less complex, like a force field or something.
As for Clark's IQ making all the other heroes redundant, I don't think that's true at all. That argument has never made any sense to me. But if it's true? Then maybe those other heroes need to step up their game. Maybe we shouldn't expect Clark to be less, because so few can keep up with him. Maybe we should ask that those who'd stand with him actually be capable of it. Maybe Superman wouldn't make everyone redundant if they didn't suck!