Well you’re also not going around holding written pieces of text to someone’s face to talk to them in real life, yet that’s how we’re communicating here, and you don’t seem to find that weird. It doesn’t need to be the same to be a helpful analogue. Sounds from your mouth -> written text, facial expressions and gestures -> emoji/emoticons. There’s actual research demonstrating that people actually do parse and react to emojis and emoticons in the same way they would to real facial expressions.