I don't like Teams, but am forced to use it for work because they don't support Slack. They don't support it for a pretty practical reason: they've spent a lot of time vetting Microsoft's security, SLAs, etc. So have our customers. Slack is a new variable that introduces more work and cost.

Leadership basically sees Teams as a version of Slack that is already integrated into Outlook and Office. Slack doesn't offer enough for them to switch to it. That would also require clearing it with all of our customers, too, for communicating about customer projects.

Microsoft has something Slack doesn't have: a built-in customer base that is already fully committed to their products.