It’s just that there’s no precise parallel between the Latin perfect and imperfect “tenses” (and yes, they are called “tenses” in Latin pedagogy, but in my fantasy world, they use the proper names for things like that in teaching. Also, I have a pony.) English does of course have ways to express what is expressed by the imperfect in Latin - the trouble is, we don’t have anything like a simple verb ending to do it. We have “I used to [blank]” or “When I was a child, I would [blank] every day”, or just plain “When I was in college I *[blank]*ed all the time” (which is expressing it lexically - through word choice - rather than grammatically.
English isn’t FUBAR at all in this respect, though - Latin has very rich verb morphology. Some languages have even more. Some have a lot less - Chinese, for instance, has an aspect distinction between perfect and imperfect, but it has no tenses at all, so to signify that something happened in the past, you have to rely on context, or else specify it lexically (for instance, to paraphrase a Chinese sentence, “Yesterday I go to library”) - no special verb ending at all. I’m not trying to nitpick here - I’m just hoping to show that the Latin style of lots of verb tenses and aspects and moods and a grammaticalized distinction between active and passive is only one way languages can work - English isn’t weird at all just because it differs from Latin in that respect.
Would it? I don’t speak Latin beyond a few words, but I do speak Spanish and some Portuguese and French, and a tiny bit of Italian - and none of them are so similar to Latin that it would be easy at all to have a conversation that way. On the other hand, if you learned Spanish, Italian, or Portuguese, you could be understood (albeit slowly and haltingly) amid communities speaking any of the others. (French is vastly different from the other Romance languages in its phonology; knowing Latin wouldn’t help in the slightest in trying to speak French.) If you’re traveling in the Romance world, it seems like any of the Romance languages would be a better choice than Latin.
In sheer numbers, more people speak Mandarin (as a first language) than anything else. By about twice as many, actually. Of course, Chinese is of limited use outside East Asia. But - and I’m not trying to be argumentative, so please don’t take it that way - I simply don’t think there’s that many Latin speakers in most countries. I think you’d probably do better with French or German in most places, including China. I have no numbers to back up my suspicion, but you made the assertion - can you back it up with anything? Latin used to be common throughout Europe, but it’s not common even there anymore, and I’ve never heard anything to suggest that Latin scholarship was at all common in Asia. There’s some Latin speakers everywhere, to be sure, but (outside the Vatican) how many places have more Latin speakers than French speakers? French is useful in large parts of Africa and quite a few places in Asia as well. Germany doesn’t have the same colonial history which means it’s not a common first language in that many places, but there’s a lot of German speakers out there anyway. There’s just not that many Latin speakers at all, as far as I’ve ever read.
The trouble is English doesn’t truly have an imperfect - not according to any analysis of English grammar I’ve seen. Lemme check - I have an English grammar right here. In Pullum and Huddleston’s A Student’s Introduction to English Grammar, English sentences can have an “imperfective interpretation”, but there’s no explicit marking for the imperfective aspect. That is, English has mechanisms to express the same things, but it’s not done through a verb tense or an aspect marker. English verb morphology is substantially different from that of Latin.
I agree completely that learning Latin can help you understand English grammar better, but I think the same could be said for any foreign language. I had similar experiences with you in high school Spanish classes - learning another grammar helps you realize what you’ve been taking for granted in your native language. But then, I think a lot of it is simply that only the most rudimentary grammar is taught in English classes, and a lot of it is frankly wrong.
There’s lots of reasons to study Latin - for one, Latin is a beautiful language in my opinion. And even the little Latin I know is useful to a surprising degree in learning technical vocabulary in other fields. But it’s not all that useful in traveling the world, which is why I think learning any of several other languages makes more practical sense.