No disagreement that free speech is important, but the solution proposed up-thread wouldn't safeguard it. In practice, it would instead limit controversial content to only a small set of sites while everything else (for fear of lawsuits currently headed off by S230 protections) would either close shop or become more moderated than it already is.

... This is in addition to the legal / philosophical criticism that the government repealing S230 protection for all but a few websites would be equivalent to the government providing libel-lawsuit protection to only a few state-sanctioned media outlets. Wholly incompatible with the first amendment.