Good technical interviews are generally looking to see _how_ you approach solving a problem more than whether you can ace it. There are also soft skills being tested like whether you can collaborate, communicate your approach, test assumptions rather than getting caught in a rabbit-hole, etc..

There may be some correlation with IQ as you propose (correlation isn't causation), but I can state unequivocally that there are people who have nailed tech interviews that had lower IQs than people who ... did less well.

Ultimately the premise seems shaky here - technical interviews are testing work-specific competence, not some outmoded and arbitrary "intelligence" metric which (to paraphrase the inventor) _was only ever supposed to be used to test for people who needed extra support_

Or to put it another way: if I'm hiring a carpentry apprentice, I probably want to know if they're likely to hit me or themselves with a hammer.

That likelihood might generally correlate with IQ, but pretty sure there'd be both great and terrible candidates across the full spectrum