The main question I'm struggling with is whether "neutral" people get more or less stupid by being exposed to the previously obscured idiocy (or deliberate nonsense).
The jury is still out on that.
What has been clear over the last decade or two is that facts, reason and logic doesn't automatically win in the "marketplace of ideas".
In Romanian we say: "don't act stupid, you risk staying that way". So the folk wisdom would be that neutral people do get stupid. It makes sense, the brain is like a muscle, if you don't exercise it, it withers (at least a bit).
And despite how we feel about it, the solution will probably be what we've always done: we promote what we think are good things and demote what we think are bad things (i.e. if you want to take it to the extreme, you can call it censorship, propaganda, etc.). The internet is also slowly getting filtered and I don't think we're losing much for it. Most of the stuff out there is garbage, as you've noticed.
Ha, I just realized the same last week while listening to a podcast miniseries about the Habsburgs, who ruled a large part of Europe for about 1000 years, but not all of them were that bright. https://www.bbc.co.uk/sounds/play/p06cqzx5
Society was always idiocracy, it was just obscured. If anything, the internet is one of our hopes for improving things.
But change is rarely short and painless.