For comparison, here's a 2004 paper on how teens spent their time from 1981-2003: https://www.youtube.com/watch?v=0-w47wgdhso
(Short version: about 5 hours a day on tv, games, and computers.)
And, let us not forget when, in 1959, Scientific American denounced the vile scourge of chess: "A pernicious excitement to learn and play chess has spread all over the country, and numerous clubs for practicing this game have been formed in cities and villages...chess is a mere amusement of a very inferior character, which robs the mind of valuable time that might be devoted to nobler acquirements, while it affords no benefit whatever to the body."
https://www.smithsonianmag.com/smart-news/19th-century-conce...
Speaking for myself, I'm not thrilled at the amount of screen time I and others spend... but the same has been said of various forms of print media and other things over the years; http://mentalfloss.com/article/52209/15-historical-complaint...
I doubt medieval crafters were thrilled about spending 10-14 hours a day in their workshops either. Ultimately, I think self-awareness is more important than anything, including how information-selecting creations like Youtube or Facebook are affecting our minds and our ideas, rather than focusing so much on time.