Although 97% of Android phones have encryption as an option, less than 35% of them actually got prompted to turn it on when they first activated the phone. Even then, not everybody chooses that extra layer of security.
This is entirely a messaging and opt-in problem. Encryption should be on by default and a user should have to active search to turn it off. There is very little reason not to have it on. Hopefully this starts to change. I’d love to see Apple have FileVault on by default for new users.
The message to users should be clear: secure your phone by keeping this option on.