As someone born and raised in the USA, like anything else in our country it’s a gradient and not black and white. There are plenty of people who speak eloquently and can engage with an expansive vocabulary. There also are, I’d wager almost certainly more, people who are borderline functionally illiterate for whom reading is a chore and who actively try to avoid it. Beyond that, the vast majority of folks can read and write but have a limited lexicon and have not attempted (and probably won’t) to grow their knowledge of English words. Most of us just get by and go along. I don’t know why I still am constantly surprised by just how stupid my compatriots are. Maybe I just want to believe in a better world. The sad reality is Americans, as a whole, are pretty goddamn dumb and ignorant and like it that way.