What you written about lack of scalability of emoji for me is their advantege over gifs.

To understand a meaning of a word/emoji/gif you have to see it in context several times or look up a definition. (with emojis and gifs there is additional problem in lack of dictionaries for them). When amount of words in a language is finite or they are extending slowly (emoji) I ma able to keep up with thier meanings as opposed to gifs and memes. Which are evolving to quickly for me to keep up.