Why I personally don't use emoji that often, especially on Lemmy, in no particular order:

• I don't feel the need to indicate emotion or facial expression as much as in a personal conversation.
• combination of a high resolution monitor I'm sitting kind of far away from makes most of them look like nearly identical yellow circles.
• There's like nine variations of sticking tongue out. And a lot of them were decided by the Japanese so a thing that looks like it's teasing officially means "I AM DISRESPECTFUL TO DIRT" so emoji are generators of misunderstanding. Especially when different systems render them differently so a face that looks scared on a Samsung might look angry on an Apple or like an office building on a PC.
• I'm on a PC, typing on an actual keyboard. To insert an emoji, I have to move my hand to a mouse and navigate a menu. That menu isn't provided by the system itself; it may or may not be provided by the text box itself, and they're all different and have their own quirks. And I'm sick of learning them.
• I just can't help it, the habit some folks have of either replacing nouns with emoji aka "I went to the 🏜️ and crammed a 🌵 up my 🍑 and now it's ⭕ " or even worse the MLM Hun tactic of typing the word outright then adding a corresponding emoji just feels childish and dumb to me.

Call me an old man yelling at cloud if you want but simple shit like :) worked for conveying emotional tone or facial expression in a way that emoji just don't. Like consider these two: 😀 😃 "Smiling face" and "Smiling face with big eyes." Without them right next to each other, you probably wouldn't realize the difference, so why are they both in the standard?