Yes, I understand that, but what I don't think you account for is the immense dampening effect that kind of liability would have for speech on all sites.

Why would any sane publisher allow unexamined but legally-actionable content to appear on their site? It's an unbelievably risky business model.

So, instead, you would have everyone competing to do the best at allowing only vapid irrelevance. Want another cat video? Great! Politics? Um. Social justice, or opposition to specific ideas for advancing social justice? Heck no!

As a lawyer, how would you advise a client who has a social media company and who wanted to limit their liability? Would you honestly tell them that it was a good business plan to allow people to criticize Israel?

Never mind if they'd win the lawsuit. Your client doesn't want to spend a bunch of money to win cases, they want a profitable business. How would you advise them?

(Note--I didn't say that young people are less likely to believe misinformation, I said it was less consequential right now. I didn't object to teaching media literacy, just that it was likely to be an important part of the solution over the timescales for which we need a solution.)