Much of the eye candy is functional, not frivolous anyway.

This is the false dichotomy.

Being able to apply slight styling to text is better than wrapping words in asterisks or underlines. Adding reactions and emojis is better than using punctuation to simulate it.

It's really common to confuse "what I'm used to" with "what's better" and I think that's especially happening here.

In what world being able to read offline messages is "frivolous eye-candy"?

Sounds like a functionality to me

edit: sounded a bit impolite. I was trying to point out, that just covering all needed functionalities doesnt mean anyone will use your product. Frivolous eye candy, ie the appearance is a key aspect for quite a few people. The issue is not that its dismissed as eye candy, but that being eye candy is an important point to look out for.

I cannot fathom how people think that communicating in something other than pure text is eye-candy. A picture is worth 1000 words as they say.

Why would you want to reach those people? Avoiding them sounds like a feature!

It's the same kind of question like "Why would you want to hire people that don't want to do our algorithm puzzles/don't want to call themselves coding rockstars/don't have the same interests outside work". It's restricting the people you interact with along more or less arbitrary lines that are not a reliable indicator of quality/usefulness.

People like to frame it as "if they can't even figure out IRC", but that's a straw man. Nearly everyone can "figure out IRC", the question is if they want to bother with it when there's alternative things they could do.

(and I say that as someone who by far prefers IRC over every other group chat system)