End-to-end cryptography is tricky (Score 1)

People are forgetting that WhatsApp (supposedly) uses end-to-end cryptography, while Telegram, for instance, can use it but doesn't by default -- and that's why Telegram usually works quite well on multiple devices, has conversation history saved in the cloud, etc. Because of that, WhatsApp requires your mobile to be connected even if you're using the desktop version: there's end-to-end cryptography connection between clients, and probably another one between your mobile and your desktop. Is there another safe way to do it? I can't imagine any.