This analogy, like most analogies, confuses more than it clarifies. It sounds plausible but it's disanalogous in ways that make the analogy more of a rhetorical device than something useful. You should just appeal to first principles and make the direct case that social media companies have too much power over speech and can be used by the US government to bypass the First Amendment. Which is a case that I would probably disagree with unless the specifics of what you wanted to do in response were fleshed out. The problem here is with the US government, not with social media companies.