In our company we work a lot remotely and everyone is in chat when working hour. Emojis are used a lot. It's much less disturbing if n people give a thumbs up to acknowledge a message instead of everyone typing a new message "OK". Especially when they read hours later.Also "working on it" is common if someone reports a problem.
Additionally emojis serves a social purpose. Instead of chatting in the office kitchen there are all kind of humorous reactions.
Same for us. If I write in the general channel that I will be five minutes late for the meeting, I don’t need everyone to say, „okay, thanks for letting us know“, a simple thumbs up from someone is enough to know at least one person has read this and will inform the rest, if necessary. And that goes for a lot of situations - I’m gonna deploy, looking at this bug now, just ping me if you need help… all of those messages don’t warrant a full reply, just a short token of acknowledgement or appreciation is enough and doesn’t force you to come up with a polite string of words that do the same thing, but more verbose.
Additionally emojis serves a social purpose. Instead of chatting in the office kitchen there are all kind of humorous reactions.