Discord has the best chat UI and experience of any similar tool. Slack is a close second, and Teams a distant third. If Slack can figure out their infrastructure issues, and undo many of the poor UX decisions from the past 12-18 months, they can beat teams. However, if Discord decides to move into the business world and offer a competitively priced product, I could see that doing very well. I honestly don't know why they'd do that, but a business version of Discord is very attractive to me at least.
I think there's a lot that could be done in regards to navigation around. Like it works, and it's clear it's inspired from the more mainline chatting interface that's been around for what feels like centuries. But any time I'm using the default client, if I'm not using hotkeys or ctrl+k to navigate across channels, there's just way too much clicking and scrolling. Not to mention you can only have one active chat buffer on display.
There's room for improvement in modern chat apps that the previous generation didn't shy away from. But it's hard to please anyone with change, but it still think that there should be experiments into some big changes
