I remember sometime in highschool a chat I had with a friend over some messaging app (Facebook Messenger?). This was before emoji or stickers were widespread.
Our conversation took the form:
actual message *emotion/tone/action*
We mused on how much clearer it made the conversation, but the extra effort required meant that it didn't last long
Now that (smartphone) keyboards have emojis that are easily accessible, it is slightly easier to do the same, maybe even fast if you have a small set that you often use, otherwise you're still stuck with typing out a search term.
This brings along another problem: how do you read emojis? They all have canonical names in unicode, but can you really guess right all the time? Even those that have been coopted for a different meaning? With different emoji fonts between devices? What about the concepts that do not have a specific emoji?
I think emoji are the modern hieroglyphs, arcane, hard to write characters that only few will truly understand.