IQ doesn’t actually mean much. Stephen Jay Gould’s The Mismeasure of Man is a good place to start. IQ varies wildly based off socioeconomic status, education, age, amount of sleep, whether or not you’ve had any stimulants/depressants/any mind-altering substance, how much you’ve had to eat, if you’ve mentally or physically exerted yourself, and so on.
Tracking IQ within an individual could be useful as part of a battery of other tests to predict cognitive degeneration, but a decrease in IQ could simply mean you’re having a bad day.
Additionally, intelligence is genetically variable, not genetically determined. It has much to do with environmental, social, and cultural factors, enough to make the genetic component not very important. That means that it’s always possible to increase—through education, practice, etc.-- your IQ, just as it’s possible to decrease it—through drugs, disuse, dogmatization and false beliefs, and so on.
I have to admit I’ve seen this as a strong motive for creating AGI in both myself and others. Maybe it’s because I just don’t get along with other humans very well (or specifically I fail to model them properly), or because I feel as if I would understand AGI better than them, but it just seems much more appealing to me than having an actual child, at least right now. Specifically, my goal is (assuming I understand correctly) non-goal-directed bounded artificial intelligence agents, so… it’s pretty similar, at least. It’s certainly a strong enough motive for some people.