Just don't sign up to any of the biggest three once the protocol reaches mass adoption, and that's not a problem because you can always leave without losing the ability to communicate if someone does something shady, and your private data is private.

Additionally having a long tail with 30-70% of the users makes it impossible to buy. And you probably don't even have to go that far, just not using element is probably enough to prevent matrix from trying it even if they wanted to (which it's clear they don't because they make it easy to leave).

We don't have to 'leave email' or 'leave tcp/ip' every few years because the TOS requires handing over your firstborn or because http is running experiments to see how many people will commit suicide. The idea is borderline-incoherent.