For fun there are other variants of base64 in a similar spirit [1][2] full unicode. [3] see other links in that repo... Not a stream cipher, just encoding but could be used in conjunction with a stream cipher to add compression. It could go turtles all the way down.

[1] - https://github.com/qntm/base2048

[2] - https://github.com/qntm/base32768

[3] - https://github.com/qntm/base65536

Emojis have a high overhead, a single emoji is typically 4 bytes but may be up to 35 bytes.

Yikes! Imagine if people were to start sending photos and videos to each other!

Oh, my bad - I wasn't aware that we're doing serious engineering here :p