I’ve barely ever used threads, in a large part because they don’t have a fully functional website and require use of an app. So I have no idea… I assume there’s some quality content but I agree that it must be flooded with BS too. I’d be interested in seeing what a Lemmy instance connected to threads looks like. I assume it would wreck browsing ‘New’.
Generally you own what you post, but you have given a license to the site to display and use it. In the US, social media sites are protected by something called Section 230. This allows sites to display user-generated content without being liable for legal issues related to it, as long as they do a decent job of trying to moderate clearly illegal content.