I don't know where I read it, but apparently older people use emojis to feel 'with it' and cool, whereas the younger crowd barely use them. (I could be wrong, and I have no source, so don't quote me on this).

Also emojis are yet another data point to do things like sentiment analysis, and have been weaponized by social media companies to target more relevant ADs at you. Tweeted/X'd the beer emoji? Get ready for Heineken ADs.