Exactly. I think the general consensus last I read is that there are nine main "types" of intelligence, but most of them are relatively difficult to measure with great accuracy. Of the nine, the types of intelligence an IQ test tests for is the easiest to test for accurately. You're recognizing pasterns, using logic, ect. You'd see far more accuracy in testing for IQ than for interpersonal intelligence for example. It's easier to fake being able to understand emotion than it is to fake understanding a mathematical pattern. Probably also adds to why there is no test that is as well established or shows as clear of a correlation as IQ.

Within the system of human society, the things IQ tests for, i.e. pattern recognition, visual/spacial awareness, logic, ect are what carry you farther than anything else on average in almost every field and are the attribute that are the easiest to quantify and scale. It's pretty hard to find a correlation in something else if you can't even accurately test for it.

Almost like how in CS:GO for example, if you have insane aim and movement, that'll carry you individually farther than anything else realistically. That's the attribute, within the system of CS:GO, that is rewarded the greatest. It's the attribute that's easier to scale accurately. It probably has the highest correlation to individual success. The other aspects of what make a player good are a lot harder to quantify so creating a scale for those attributes becomes a lot less accurate so the correlation isn't as strong as well.