There's a bit of misunderstanding. Pavel is talking about backups to Google Drive / iCloud that you do in order to preserve the messages and move them to the ot

There's a bit of misunderstanding. Pavel is talking about backups to Google Drive / iCloud that you do in order to preserve the messages and move them to the other phone. While it's true they aren't encrypted, it makes a lot of sense for such a mainstream product — I wouldn't imagine the app asking people to save a private key for it. All communication itself is E2E-encrypted with WhatsApp. Telegram doesn't have that by default but in return the app is available on multiple platforms and these instances work independently with great cloud sync.