I've semi-recently created a new Twitter account account in order to dive head on into the deepest cesspools of Twitter. The topics and accounts I follow are mostly what I'd call "bot bait"--stuff like Hong Kong, Trump, COVID--and it's been extremely eye-opening to see the ways that people will respond back-and-forth for multiple tweets in near real-time.
But I've also come to roughly the same conclusion as you. I might be naive, but given the time I've spent on the internet, I'd like to think I can tell the difference between bots and humans. Some of the bots are obvious, some of the bots are non-obvious (blaming bots), but still definitely bots. But MOST of them, are probably real people. Really, really ignorant people, on all sides of the political spectrums. There's just these people out there now with phones and a Twitter account, and they're broadcasting their id.