It's not just USA, it's pretty much universal, as much as I've seen it. People like to pretend like it's some sort of noble profession, but I vividly remember having a conversation with recently graduated ex-classmates, where one of them was complaining that she failed to pass at every department she applied to, so she has no other choice than to apply for department of education (I guess? I don't know what is the name of the American equivalent of that thing: bachelor-level program for people who are going to be teachers). At that moment I felt suddenly validated in all my complaints about the system we just passed through.
I went to public schools in middle class neighborhoods in California from the late sixties to the early eighties. My teachers were largely excellent. I think that was due to cultural and economic factors - teaching was considered a profession for idealistic folks to go into at the time and the spread between rich and poor was less dramatic in the 50s and 60s (when my teachers were deciding their professions). So the culture made it attractive and economics made it possible. Another critical thing we seem to have lost.
What I take from this is that you dont like reading about history much, with clear exception of overly optimistic religious texts. The religious vocation frequently got you into pretty abusive situation and the #1 expectation was "obeisance". That was what you was supposed to do, primary. Not exactly what person you are responding to is writing about.
Moreover, women never needed to start out as teachers to "be ready for childcare". The childcare expectations were much lower at the time, but amount of chores at home massively higher.
Sounds like a self-fulfilling prophecy. We educate everyone to be the smartest person in the class, and then we don't have jobs for them. And then we complain that education is not good enough. Shouldn't we conclude that education is already a bit too good?