30% cpu at idle with 5 accounts.
50% if I enable emojis.
Like I'm sorry but it's essentially IRC. There is zero excuse for being that much of a hog.
You can blame it on electron if you like (I do) but it doesn't change anything for the end user.
It's irc with emojis, 2mb animated gifvs, embedded hd video and other complex content rendering. Of course it's using as much ram and cpu as a browser.
Yes it often makes sense to produce inefficient code for many business reasons (development speed, users don't care, easier platform to deploy to, etc).
However what Slack does would be nowhere near taxing for a modern computer if it were to be done remotely efficiently.
It's why you use Slack, rather than why people use Slack. I'm sure you could make do without the emojis, GIFs, and videos, but the market says people seem to think otherwise.
(Ok, I remember HipChat didn't have gifs but there was a lot else wrong with HipChat)
Slack is nicer than IRC to use. Nobody here is debating that. Slack solves a heap of problems with IRC.
My only point of contention is that there is zero argument for it using the resources it does. None of the mentioned solutions require any more resources than IRC consumes.
We just have a big heaping pile of electron nobody wants to acknowledge as the source of the problem.
This is a fairly modest i7 3770k based system. Their work on reigning in runaway CPU usage truly seems to have paid off.
Slightly mitigating data point: Other Electron apps do this too.
Your link is not really relevant here because it talks of business viability not program performance.