I typically feel like people like this aren't dumb, they're just so incredibly distrustful of authority figures like teachers or scientists or the government that on some level they reject reality and when videos "kinda make sense" or "have some points" about shit we all know is fake, it gives them the ability to choose what they think is correct and because they're already rejecting what they're being told is real by people they don't trust it's really easy to let conspiracies fill in the gap of how it works