Every college I know look for students that challenge themselves academically and taking AP, IB, and Honors class demonstrates that.
The reason most colleges use unweighted GPA is because different schools give weighted values to different types of classes. By taking the weighing out, it give them level view for evaluation. That should not be confused with its not important nor not needed.
To advise someone, who is less than "super academically gifted" (whatever that means) not to take any AP or Honors classes to avoid rigorous classes, would be a mistake in my mind.
Another reason to take AP classes, then the AP tests, is to gain college credit. One can argue if its one for one or if they accept just passing score versus 5/5 score on the tests, in most cases, some credit is given to the students for doing so.
I know many students that took AP classes and passed with 3/5 and gotten UC and Cal State school credits, and entered their freshman year with sophomore class standing. In other words, the likelihood of them graduating sooner is greater (i.e., less tuition due to shorter time spent=lower costs).
As for Ivys and other top 20 academically ranked schools, one is definitely at a disadvantage without APs because all others, including soccer players/athletes, all have plenty of AP classes. One of the key criteria for many of those schools is that the athletic population should be representative of the entire college. Meaning that should be close to the non-athletic general population.