There was an old rumor that the High School Graduation Qualifying Exam (HSGQE) from the mid-00s was actually only geared to test an 8th-9th grade intelligence, yet was a metric suitable to rule the student qualified to graduate. Many jokes were made of why we were still there then to finish 10-12th.

That said, we need to keep kids in there until 18. Not only because we'd have an idle population of teens without jobs if we didn't keep them in school, but studies at university and college levels have found radically increasing needs for remedial courses (sub-101 level), particularly Math and English to bring high school graduates up to college caliber. Public schools aren't getting our students there.

We should improve courses, and bring back vocational type classes such as shop to give students wider diversity in their education, and also let them find that maybe they want to pursue vocational learning as opposed to college learning.