I use WhatsApp for personal messaging related communication. It has end to end encryption at the moment and it prominently shows that when you chat with anyone. In fact for end to end encryption, both people need to have newer version of the app. If anyone does not have the newer version, it shows that end-to-end encryption chat is not possible with this user.
I like that end-to-end encryption is the default in WhatsApp. They are experimenting with business models in which only the end users would need to read the message. Hopefully that model would work :) However I understand how people might be able to accept that Messenger chat is being analysed in real time by Facebook. But I think countries like Germany etc. where people are not comfortable with someone intercepting their messages would see usage of WhatsApp and Telegram instead of Messenger, both of which have default end to end encryption.