It is also worth mentioning that Whatsapp relentlessly buggers you to backup to Google Drive or iCloud respectively, where all messages and contents are stored

It is also worth mentioning that Whatsapp relentlessly buggers you to backup to Google Drive or iCloud respectively, where all messages and contents are stored in plain text (at least on Drive, not sure about iCloud). It's nice that they advertise end-to-end encrypting the messages in transit, but then just dump everything to the world's biggest data mining machine.