It's a gut feeling but it's a very valid one. Its been measured and validated among so many metrics that it's pretty solid that performance any intellectual task will highly, highly be inline with IQ. In psychology it's one of the few quantitative metrics that so solidly predicts a lot of things.

What seems seems disingenuous to me is sometimes people can't hold and opinion without hard data. Do you really need raw data to know you shouldn't hire a person with an IQ of 45 to drive a bus?

No most people don't need data. I think what's going on here specifically is that a lot of people don't do well on leetcode and they know it and they don't like to think that it correlates with their general intelligence.

I'm truly sorry for making some people face that reality. I would say I'm not the best performer on leetcode myself. I can't deny that even without raw data it's pretty solid that IQ will correlate with leetcode performance. There are other correlative factors too like studying for leetcode specifically. And I don't need raw data to make either of those statements.