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.