This is such a bad, bad thought.
Without high school sports, there are literally thousands of high school kids in my city alone who would have absolutely no opportunity to play organized athletics at an age when it's absolutely vital for them to be engaged in extracurricular activities.
Not everybody is playing sports at a high level for the purposes of getting a scholarship or going pro, and I'd bet my life that the people who run these organizations you hope kill off high school athletics would cut off their own heads before they'd offer all these kids the chance to play for free.
I was just about to write the same thing as CoachJD...there are certainly issues with many HS programs but the opportunities to play or learn a new sport while in school is huge. If it all goes away and becomes a "private" deal there will be many kids who never get to even experience most sports.