Having lots of features is one thing, winning adoption is another. Microsoft lacked a unifying piece that would integrate these various elements into a form that users could easily embrace. Teams is that piece. Introduced in March 2017, I initially thought there was nothing much to it: just a new user interface for existing features like SharePoint sites and Office 365/Exchange groups, with yet another business messaging service alongside Skype for Business and Yammer.
Original: https://www.itwriting.com/blog/10883-on-microsoft-teams-in-office-365-and-why-we-prefer-walled-gardens-to-the-internet-jungle.html