You're being deliberately obtuse. Canvas has many many features. Wikis and discussion boards and quizzes (with some anticheat) and groups and the list goes on and on. Furthermore, while it was never the flashiest thing, it did it better than many of its predecessors. Yes, an individual class may not use all of these features, and yes canvas has suffered feature creep even over my time as a student and yes canvas is not doing anything technically challenging, but there is enough of it that each school rolling their own everything would be a drastic waste of everybody's time and money.