I'm sorry, but channel chat certainly is not like IRC. Threads and reactions, and to a lesser degree multimedia, make a drastic change on the experience. Those

I'm sorry, but channel chat certainly is not like IRC. Threads and reactions, and to a lesser degree multimedia, make a drastic change on the experience. Those three features allow conveying a lot more information in a smaller cognitive space. Threads allow smaller groups of participants to carry on with a conversation for a long while without hogging the chat and without making it any less public. Reactions allow showing support or many other kinds of sentiments to someone's statement with a tiny bit of vertical screen state for huge swaths of people, doing the same on IRC is wholly impractical. Multimedia is an obvious convenience. Having to rely on external or ad-hoc services to support it is annoying at best, anti-user at worst, meaning people often just don't share anything at all because most don't think of the medium as multimedia capable. I do think that desktop chat applications should not be the bloated abominations they are, but any less than the experience that software like Slack or Discord provide would be a worse alternative to the overwhelming majority of people who today use and enjoy either, no matter how optimized.