WhatsApp vs Signal vs Telegram : Which is The most secure app 2021
WhatsApp does not encrypt backups (cloud or local). Whatsapp also does not encrypt metadata unlike Signal, which is used to carry communication between two endpoints. WhatsApp group chats have been earlier found to be indexed on Google search, major data breach point.
Telegram group chats are not encrypted unless you use Secret Chats, which again only supports single-user communication.
In terms of user privacy, Signal offers the most secured form of communication you can get on the internet. But again, Signal lacks a host of features if compared to Whatsapp and Telegram. Signal by default encrypts all the local files with a 4-digit passphrase. It also supports encrypted group calls.
The last comparison table shown in the video is from The Indian Express website.