Some insight from Eliot’s essay “Religion and Literature” (1935):
Now what we get, as we gradually grow up and read more and more, and read a greater diversity of authors, is a variety of views of life. But what people commonly assume, I suspect, is that we gain this experience of other men’s views of life only by “improving reading.” This, it is supposed, is a reward we get by applying ourselves to Shakespeare, and Dante, and Goethe, and Emerson, and Carlyle, and dozens of other respectable writers. The rest of our reading for amusement is merely killing time. But I incline to come to the alarming conclusion that it is just the literature that we read for “amusement,” or “purely for pleasure” that may have the greatest and least suspected influence upon us. It is the literature which we read with the least effort that can have the easiest and most insidious influence upon us. Hence it is that the influence of popular novelists, and of popular plays of contemporary life, requires to be scrutinized most closely. And it is chiefly contemporary literature that the majority of people ever read in this attitude of “purely for pleasure,” of pure passivity.
The relation to my subject of what I have been saying should now be a little more apparent. Though we may read literature merely for pleasure, of “entertainment” or of “aesthetic enjoyment,” this reading never affects simply a sort of special sense: it affects our moral and religious existence. And I say that while individual modern writers of eminence can be improving, contemporary literature as a whole tends to be degrading. And that even the effect of the better writers, in an age like ours, may be degrading to some readers; for we must remember that what a writer does to people is not necessarily what he intends to do. It may be only what people are capable of having done to them. People exercise an unconscious selection in being influenced. A writer like D. H. Lawrence may be in his effect either beneficial or pernicious. I am not sure that I have not had some pernicious influence myself.
One can only imagine what Eliot would have concluded about the influence of movies, TV shows, and YouTube videos on our “moral and religious existence.”