A key part of the New York case against Trump was the “catch and kill” “scheme.” Of course tabloids aren’t required to publish stories, just like social media websites aren’t required to publish links. But in the Trump case that was deemed election fraud.
A key part of the NY case was also that Trump, the actual candidate, was a causal agent in the catch and kill scheme which, it was argued, violated election laws. What does the case against, say, Twitter look like? They weren't running for office or a part of any candidate's campaign.