Rules usual have a basis in reality otherwise they be arbitrary, random and not predictable.
Exactly when I have rules that predict reality or approximate it I have a model, if that model is so logical and so perfect that is 1 to 1 with reality have a model theory, that allows me to know things, that those with more poor modeling don't have.
How do I know what is real. I have rules that when I apply them I get to see outcomes that conform to my predictions.
The higher IQ the more robust modeling I can make, the more predictions I can make the smarter I can benefit from my prediction, the more I get done in reality with less effort, the more I can do with less effort in less time, the more intelligent I am.
However not all things can be done quickly. Lots of people for example can equate intellect with speed. However in real life somethings, especially very valuable things like building pyramids takes years of hard work and planning. So it would not be IQ that lets me built pyramids alone.
Lots of things require hard work so that means lots of people with high IQ who only do things for quick results will always be beaten by people who put in the work and are more focused.
This means you can get 100 IQ billionaires and 160 IQ idiots who live in moms basement.
The point is tho every time higher IQ people model the world they get to be more closer to reality overall, with higher resolution.
The other problem is that we cannot use max capacity of our brain 24 7, we need a break hence why IQ tests are 20 or 60 or few hours long, but if you had a untimed IQ test you might get different results entirely.
What happens in reality though is that human intellectual work gets spread out over time of months, years, even decades before humans can contribute to society in major way which means you have to work consistently on some things for 1000s of hours.
Conversely some people with lack of focus would have to work 10 times as hard as people who can focus.