I didn't go to high school, when I returned to the states at 16 after 8 years of boarding school, I was advised that high school would be a waste of my time entirely. I went straight to college and I have no regrets.
My daughters had miserable experiences in High school:
DD20 (MG) enjoyed 9th grade because we were in a big city that had an amazing magnet program and the high school she went to had a counselor that actively recruited the brightest middle schoolers from across the district so she was in good company with lots of challenge. She was also in an award winning jazz band that was regularly hired to play social events in the community so she had a lot to be proud of and excited about and she had awesome peers. Then we moved to a small town where the academics were a joke. She still enjoyed marching band but her counselor confessed that the school had nothing else to offer that would challenge her so she was allowed to graduate 2 years early.
DD17, (HG) was not so lucky and her sister's counselor had left by the time she was in high school. The school had nothing to offer my DD17 academically either, but they chose to focus on squashing her will to live instead. The stance was "she needs to learn the discipline to plow through the workload so she will be able to handle it in the workplace" My DD refused to do any work outside of school but aced all of her Pre AP tests and passed all of her classes with 100s on tests and zeros on busywork. I posted elsewhere about the English teacher who broke the rules in order to fail my Daughter so she could teach her a lesson (my Daughter was the only student in that Pre AP English class to even pass the Pre-AP exam but the teacher decided to dismiss the grades for that test and instead threw the weight of the grades to homework for which the deadline had already passed). In addition to the demoralizing effect of being bullied by a teacher, my DD had to deal with religious bullying from her peers who were certain my DD was going to hell for questioning the existence of god and would hold "prayer groups" for her during the bus-ride home(!) On the bright side, she enjoyed marching band.
So I guess if you have the right high school it may be a positive normalizing experience, otherwise it can be a soul crushing experience for kids that aren't average to begin with.
