Other platforms aren't subject to censoring laws.
The 1st Amendment applies to the government action, not private companies.
The bigger irony here is if these companies lose their protections from libel suits you'll see much harsher curation of content and drastically reduced conversation.
People get so caught up in their political positions that they blast their own feet off.
They are either a platform or a publisher. They cannot legally be both.
While the First Amendment generally does not apply to private companies, the Supreme Court has held it “does not disable the government from taking steps to ensure that private interests not restrict . . . the free flow of information and ideas.” But as Senator Ted Cruz points out, Congress actually has the power to deter political censorship by social media companies without using government coercion or taking action that would violate the First Amendment, in letter or spirit. Section 230 of the Communications Decency Act immunizes online platforms for their users’ defamatory, fraudulent, or otherwise unlawful content. Congress granted this extraordinary benefit to facilitate “forum[s] for a true diversity of political discourse.” This exemption from standard libel law is extremely valuable to the companies that enjoy its protection, such as Google, Facebook, and Twitter, but they only got it because it was assumed that they would operate as impartial, open channels of communication—not curators of acceptable opinion.