Access to an audience is part of speech IMO. If most of the world's population was on one continent-sized piece of private property, and because it was private

Access to an audience is part of speech IMO. If most of the world's population was on one continent-sized piece of private property, and because it was private property the owners were allowed to censor whoever they wanted, "you can go talk freely on the almost empty island over there, maybe someone from the continent will come listen!" doesn't sound like free speech to me. I agree that getting rid of algorithmic search/recommendation/promotion would be a big step forward, but platforms for speech of a certain massive size like Youtube/twitter/facebook/etc should also be heavily regulated and their ability to censor limited. They are, due to their overwhelming size, de-facto custodians of speech.