* No end-to-end encryption for desktop meaning normal use when working on computer requires you and your friends to constantly whip out phone to send 1:1 secret chats. Nobody wants to do that so they revert to non-E2EE chats.
* Terrible track record with end-to-end encryption deployment from AES-IGE to IND-CCA vulnerabilities
* Not end-to-end encrypted by default.
* No end-to-end encryption for groups.
* No end-to-end encryption for desktop meaning normal use when working on computer requires you and your friends to constantly whip out phone to send 1:1 secret chats. Nobody wants to do that so they revert to non-E2EE chats.
* Terrible track record with end-to-end encryption deployment from AES-IGE to IND-CCA vulnerabilities
* CEO pretends to be exiled from Russia but in secretly visits Russia over SIXTY times in 10 years https://kyivindependent.com/kremlingram-investigation-durov/
* Zero metadata protection from server
* Open source, but it's meaningless as it only confirms the client doesn't protect content or metadata from the server.
I think Signal is a better alternative, even though it's US made. It's open source.