When Slack is bought by Google and merged with Hangouts, and WhatsApp changes over to a new all-messages-delivered-by-the-NSA protocol, email will still exist.
Hah, Google, have multiple messaging systems and bother to merge them?
It gets tiring to convince people to install Signal, Wire, etc.
though many people are just too lazy to replace even ugly default Messaging app, so wet just use it with my wife and parents since I boycott Messenger/Whatsapp, just in case for video calls I have Skype Mingo (it's sad that out of billion people in India it's difficult to find one person which would upload always newest build to apkmirror)
Why give away your SMS to a messaging app that purposely dropped their encryption to focus on online chat which is useless to me as I don't have a data plan?
[1]: https://whispersystems.org/blog/goodbye-encrypted-sms/ [2]: https://silence.im/