There's a Unicode sequence that tries to use a monochrome glyph instead if it's supported which I prefer as it's more in keeping with the rest of the text (though an issue with some of those variants is legibility at small sizes/PPI).
Emojis in repos and CLI tools is the textual counterpart to the soulless Alegria art style: https://en.m.wikipedia.org/wiki/Corporate_Memphis
I get they bring people a little bit of joy, but as a dyslexic who likely also has ADHD, they bring me unnecessary distractions and visual clutter.
The only time I like emojis in a formal setting is when used in Slack to denote a thread (the thread/sewing emoji).
I like coloured text, and I like TUIs. To be fair, nothing I use has noticeable emojis. I am not really bothered about enhanced terminals - I would rather keep terminals simple and use a GUI if I need more complex presentation.
On top of that, there are only very few emojis that can be read properly at the same size of the current line height. It works for a few simplified faces and symbols, but that's it.
The fact that emoji fonts override the font color rendering is an aggravating factor. I don't want text to change color behind my choice (it SUCKS with customized color themes).
They feel like a punch in the face to me when I'm reading documentation or even worse when reading code.
Sadly, it's really hard to avoid them nowdays. I'm using a few lisp scripts with emacs to translate the common ones back to ascii for rendering.
I can point out that "Noto Emoji" is a b/w version of Noto Color Emoji, which contains a MUCH more suitable version of emojis that can be used in running text. As noted before, it's only a partial solution as I find most emojis are still not readable when scaled at the same size as the text and when simplified sometimes they also lose the original meaning (just use the damn word dammit!). But at least they don't override the color. On linux, you can force a font substitution with fontconfig to force the b/w version whenever color-emoji is used and can't be customized.
See the old apple gun vs squirt gun. The same is true also when using stuff like whatsapp on android, where the os keyboard shows you one image from the system theme, but the one which you see inserted in the text is not what you selected, but at least is partially better than sending something without knowing how it will be rendered, which is what most chat messages have realized after trying to simply using the system font.
So at that point, you have to switch to a different custom font just for the emoji block, and you're still limited to what unicode allows instead of just bundling whatever image you want (which is a great excuse to sell new phones with "new emojis" I guess).
https://blog.emojipedia.org/correcting-the-record-on-the-fir...
Please also see the very last guideline here: https://news.ycombinator.com/newsguidelines.html
Except that every chat client now supports stickers, which are nothing but custom images that are guaranteed to render the same way for the recipient that they do for you. The recipient does not need to have them installed.
But stickers have to be their own full message in the clients I know of. Once they start to be integrated into textual messages, clients will have developed all the way to where MSN messenger was in 2003.