Ask HN: Why are video courses and MOOCs so famous

I see that most of the well known courses/MOOCs (Udacity, Coursera, Skillshare, Pluralsight) online are all video based. Why is this so? Why have text based tutorials and courses fallen out of favour? With video, you cannot go back and forth as easily, you cannot concentrate on what you want and is generally slower than using text bases tutorials/classes.

Why have they increased in popularity inspite of above reasons?