> But Facebook (and Google, Apple, and many other "platforms") are such an indispensable part of our lives that we should have difficult conversations about what individual rights look like in these quasi-public private spaces. (It's worth noting that the explicit business model of many of these companies is to create gigantic platforms/walled gardens.)

I don't agree, I think the opposite. The government should be working to make them more dispensable. Every company you listed needs aggressive antitrust action from various worldwide governments.