> I have this view to try to increase diversity of media consumption and break people out of echo chambers.

Making sites liable for all user-posted content would do the reverse of this. Every platform that lets people submit content would have to stop doing that, because it’s an impossible liability to manage.

You’d have to host your own site. You wouldn’t be able to share anything about it on a social media site because its user-generated content. No visitors unless you advertise it through paid contracts with companies that can review it and decide to accept the liability.

Newspaper "Letters to the Editor" manage to do this. Users "submit" things to the newspaper, the editor curates and decides what to keep and what not to, and then the newspaper publishes the user generated content. Just like social media: Users submit things to the site, TheAlgorithm curates and decides what to keep and what not to, and then the site publishes the user generated content.

If web sites and social media can't "scale" to do this, then maybe they should scale down. "Making sites liable for all user-posted content" would not kill social media, but would definitely scope it down to what can be effectively curated.

I notice that parent describes "engagement" algorithms and you somehow jump to "all sites". So I think we'd see "engagement" algorithms disappear and very primitive approaches with prominent transparency measures in place would replace them. I expect we'd all be better off were that to happen.

>Every platform that lets people submit content would have to stop doing that, because it’s an impossible liability to manage.

This is a huge assumption that is offered constantly, and always, without any evidence at all.