If the client app is open source and the messaging is end-to-end encrypted, I would say it's a lot better than being completely closed. The encryption, which yo

If the client app is open source and the messaging is end-to-end encrypted, I would say it's a lot better than being completely closed. The encryption, which you should now be able to verify, means you don't have to trust the server with your message data. Though, sure, it would be better for the server software to be open source and rehostable too.