I don't know why you're being downvoted, but it's exactly this.

Pre-emojis, there were so many times I misinterpreted a text, or had a text misinterpreted. Something that is obviously a joke or sarcasm or teasing with non-verbal communication, can come across as an insult without it. When somebody adds a wink emoji or similar at the end, it changes everything.

Emoji are fantastic at communicating tone and attitude alongside the text itself. They're not a 1-1 correspondence with non-verbal communication, or a perfect replacement, but they vastly improve the chances that something playful isn't misunderstood in a negative way.