There are so many kinds of intelligence.
A person who may be "book smart" may not have any serious experience. Is one necessarily more intelligent than the other?
I may be an expert on x86, another person an expert on ARM9. Is one less intelligent?
I may be a computer nerd, someone else a social nerd, someone else a mechanical nerd, someone else a music nerd. Does that mean any are necessarily more intelligent?
The IQ score was never meant to be used the way people use it commonly. It was just a standardized test with 100 as the average score for that age and each individual score was the deviation from the mean. It is not/was not meant as a fixed number, it changes with age and experience and changes by the test you take.
I'd call intelligence the ability to apply experience, knowledge, and skills. Some people may have more of each to apply, some people may be more skilled, or more knowledgeable, or have more experience. In that respect I'm more intelligent than a child as I have much more ability to apply experience, knowledge, and skills. I could not say that I have one score and they have another score. I can say that I have more experience in an area, or that they have more skill in another area.