These are platforms for speech. People crave and seek such platforms, and frankly I think they provide a valuable service in disseminating ideas that corporate entities have no incentives to.
It verges on absurd to criticize platforms designed to transmit public speech on the grounds that they might leak that information.
There seems to be a quaint archetype floating in the collective consciousness with an image of privacy that has never existed, outside of recluses living in exile from their community.
Historically, anyone living in a small community had such a lack of privacy, that it would be intolerable to many modern city dwellers.
There needs to be a more nuanced and realistic concept of how personal information is managed, by all entities who touch it.