There is plenty of encryption used when you send any sort of message from an iPhone, even SMS. You can’t even turn the dang thing on and unlock it without encryption. Then when you send it, it’ll be encrypted by the radio before transmission. Then in transit it may or may not be encrypted at various points.
And POTS is not the internet.
My overall point is that encryption is used all of the time when people use the internet for routine tasks that they expect to work, and would not work in a modern reasonable way without it.
People use these technical implementations details to muddy the water of this conversation and demonize encryption, when the reality is that everyone uses it literally all the time for almost everything.