A colleague of mine uses through irc gateway but tells me a lot of stuff is not supported well like threads (which some people unfortunately started using more) and that you can't see edits, which many people also do. I think attachments and files are also a problem.

And slack is complete garbage that is pushed and we as employees most of the time have no other options.

Besides the whole problems mostly talked about related to memory and cpu usage, the one nobody seems to check or understand is that it is completely frustrating and unusable from accessibility point of view. I've seen this first hand as that person above is blind and the slack application is of one the worst offenders there is regarding this point. I've seen and felt his frustration and how slack team manages to avoid his point all the time.

So I hope it dies out eventually :D

Unless your employer decided to disable that option because an upper manager didn't like the idea for reasons that I don't even understand. It's even more difficult when you are part of a corporation with thousands of employees that are in favor of using Slack over IRC.