It is causing issues for forensics (before that people were using SMS, IMAP, and SMTP; all without TLS). It isn't fool proof, for example if your adversary can

It is causing issues for forensics (before that people were using SMS, IMAP, and SMTP; all without TLS). It isn't fool proof, for example if your adversary can gain access to Google Drive or iCloud via a warrant. Although making backups via such platforms is optional.