> forcing message passing platforms to submit to sharing private encryption keys?
Why assume that requirement? For E2E encrypted messaging services all that needs to be shared are public keys for interoperability to work.
In the case of middleman encrypted messaging you already trust the provider not to sell you out. If they interoperate then you trust N providers, where N is the number of providers engaged in a particular chat thread.
You say this like it is not a big deal, I trust Apple much more than I trust Meta with my messages. Apple has made privacy a cornerstone of their sales pitch, Meta not so much. N=2 is too many.
Why assume that requirement? For E2E encrypted messaging services all that needs to be shared are public keys for interoperability to work.
In the case of middleman encrypted messaging you already trust the provider not to sell you out. If they interoperate then you trust N providers, where N is the number of providers engaged in a particular chat thread.