Remember that Google Hangouts conversation you had that one time and then archived it? The good news is, it's not gone forever. Let's get it back!
As with most platforms, archiving something is very different from deleting something. Facebook Messenger's archive and delete functions can be just as confusing as on WhatsApp or Gmail.
WhatsApp might be able to back up all of your messages, but aren't there some you'd rather delete forever?