I was certainly capable of teaching myself in high school and skipping multiple years in certain subjects; why not just do that? Or find some other topic to learn about that isn't taught in school, like programming.
As a former "gifted" child—which I thought was code for "autistic" and not actually a compliment at the time, so it surprises me people willingly refer to their child as such—public school never catered to me, but I wouldn't have traded that environment for private school or homeschooling if you paid me. In my experience all that people talk about how private and homeschooling affects your ability to socialize with normal people is true.