My brother took Latin and I took French in high school and I found French to be much more actually useful in improving my vocabulary and understanding. I went to a Catholic high school and we learned some snippets of Koine Greek as part of studying the Bible. None of these were time effective at learning English at all and more English classes would've been much more effective (especially at the level most high schoolers are at).

My high school was more classical than most and it was not a better way to teach English.