The feature protects backups stored in the cloud
WhatsApp already comes with end-to-end encryption for private conversations and calls, but on the other hand, the backups that you create and store in the cloud are exposed. This is why the company announced last month that it’s bringing E2E to these backups as well, no matter if you use an iPhone or an Android device. In other words, all your backups will be protected by end-to-end encryption once uploaded to iCloud or Google Drive, so in theory, nobody but you should be able to access their contents. Of course, it also means that you may no longer be able to access your backups if you lose the password.
