It's b been done in places. Louisiana has mostly charter schools. They have a fixed per-student compensation. At least one used to be one of the outstanding high schools in the country: Ben Franklin. About 10-12 years ago, 50--FIFTY!!--out of a graduating class of 150 were National Merit Scholars. One out of every three. And it's a public school.

Unfortunately, teachers decided to join a national union. Things went downhill after that. Not sure how far--I lost touch with it during covid. But I still lurk via back channels--it was my high school. Its neo-wokeness depresses me.