A smart college coach, wanting to see and know prospects in a variety of environments and facing different stressors, will scout BOTH club and high school activities, as well as camps and other venues.
It's called due diligence.
As to the relative benefits of club and high school soccer, playing for a school, in front of friends and families, shouldn't be viewed as an ALTERNATIVE to competitive club soccer, but rather as a supplement.
One other thing: High school isn't pay-to-play. Coaches, not parents, call the shots.