Another way to save time in public schools is to blend courses.
For example, in schools that teach religious studies, why not combine English literature with religious studies by teaching the elegance of style of the KJV or Rodwell's translation of the Koran through selected passages from these books in the English literature course.
We could blend English literature and history in a similar manner by teaching students the elements of Gibbon's style through his History of the Decline and Fall of the Roman Empire in the history course. This overlapping whereby students learn religious literature in an elegant literary translation in the English literature course and elements of English classical prose in the history course would promote more efficient use of time and so allow the school to drop the religious education course altogether while still teaching the essentials of religious literature and having students learn English, religious, and historical literature all as part of an integrated literature and history education while still learning at least the essentials of history.
The time saved from this would free up even more time for trades and professional education courses.
Music class could also be integrated in this. For example, students could learn to play Renaissance and Baroque era recorder music. It's an easy instrument to learn to play and adding the historical component blends music and history class. Learning any other instrument would be viewed as a specialization just like French.
PE could be blended with learning a martial art (useful in some jobs like police officer for example) as an alternative to the traditional PE class.
We could at least explore the possibility of blending physics with electrical technology, though maybe more as a specialisation for interested students.
I might be wrong on much of the above, but I'm sure if we cut out the fat of less essential knowledge, it could free up more time for more useful knowledge.
Languages aren't hard to learn.
To learn a second language well enough for it to be practical in a trade or professional? Most are quite difficult to learn to that level, unless we're talking about a language that is easy to learn by design or if language becomes the student's specialisation.
Bear in mind though that I'm playing devil's advocate here in imagining that the student will have to use his skills in the job market right after graduating from high school.
I understand many will continue on to college, but I'm thinking more about those who can't go on to college. For them, it's essential that what they learn in high school can already get them at least decent work.