Source: Lightspeed Ventures
We use slack in the office. In many ways, it is superior to email; where it fails is when it tries to be a substitute for actual face to face conversations and collaboration.
Slack has been so successful that there are now dozens of competitors, many in very specific niches (see graphic above). Merci Victoria Grace of Lightspeed mapped out eight categories of collaboration software: Messaging, Voice & Video, Calendar & Meetings, Documentation, Project Management, Design, Search & Context, and Low Code/No Code & Internal Tools.