Content moderation isn't free speech, it's freedom of association, or in constitutional terms, freedom of assembly.
Consider that Ben Franklin wouldn't publish libelous or slanderous material submitted to his newspaper - clearly a form of "content moderation." He believed in the right of the people submitting such things to express them and would suggest they try elsewhere, but also believed in his right not to publish those views on his "platform."
I don't think anyone would accuse Ben Franklin of not believing in free speech, so clearly a reasonable person can square the apparent circle. Freedom of speech isn't the only right relevant to speech, and freedom of speech doesn't guarantee a right to speak on all platforms.
Consider that Ben Franklin wouldn't publish libelous or slanderous material submitted to his newspaper - clearly a form of "content moderation." He believed in the right of the people submitting such things to express them and would suggest they try elsewhere, but also believed in his right not to publish those views on his "platform."
I don't think anyone would accuse Ben Franklin of not believing in free speech, so clearly a reasonable person can square the apparent circle. Freedom of speech isn't the only right relevant to speech, and freedom of speech doesn't guarantee a right to speak on all platforms.