He talked about it in multiple places, but Although of Course You End Up Becoming Yourself (an interview) discusses it a lot.
https://www.goodreads.com/work/quotes/7144014-although-of-co...
What explains the pointlessness of most published TV criticism is that television has become immune to charges that it lacks any meaningful connection to the world outside it. It's not that charges of nonconnection have become untrue. It's that any such connection has become otiose. Television used to point beyond itself. Those of us born in like the sixties were trained to look where it pointed, usually at versions of "real life" made prettier, sweeter, better by succumbing to a product or temptation. Today's Audience is way better trained, and TV has discarded what's not needed. A dog, if you point at something, will look only at your finger.
[0] https://www.thefreelibrary.com/E+unibus+pluram:+television+a...
> Television will achieve its apotheosis when it is interactive.
> Of course, some people think they have that now. For some people, TV reality is as much of a reality as what they move through most of the day. I remember listening to two people I used to work with discussing the horrible burden a character on a TV series would have to bear for causing someone's death in a fire. These were not uneducated or isolated people; they had simply been drawn in so far, they were projecting the characters well beyond the end of the show -- indeed, beyond the life of the series itself. And we've all heard amusing stories about actors who play soap opera villains suddenly attacked by irate viewers who cannot separate actor and character, Maybe more people can't than can -- the host of Death Valley Days was President of the United States for eight years.
> Does TV encourage, or even induce, schizophrenia? Or does it create a separate reality in conjunction with our minds, something that is neither totally our inner life nor totally TV. The networks might call that programming.
Marshall McLuhan explained how humans see tools - such as media - as an "extension of ourselves". It's important to keep this in mind when creating tools or types of media: you're also defining part of the human that uses the tool.
[1] The short story "Patterns" was originally published in the August 1987 issue of Omni.
http://www.marshallmcluhanspeaks.com/lecture/1977-man-and-me...
"The Mirror of Erised is an ancient, ornate mirror. It has clawed feet and a gold frame... The mirror shows the most desperate desire of a person's heart, a vision that has been known to drive men mad."
"Men have wasted away before it, not knowing if what they have seen is real, or even possible." —Albus Dumbledore explaining the danger of the mirror to Harry Potter
(This miight be the one - “informing ourselves to death”: https://m.youtube.com/watch?feature=youtu.be&t=1487&v=fuRVxW... )
Its interactive nature is another difference of kind not shared with books or television and likely to increase its addictiveness.
Also, the literary broken narrative effected by story-length footnotes that had story-length endnotes imitates the short/shattered attention span experience of living that DFW was already able to feel and express—and Infinite Jest was published over twenty years ago.
I escaped into Infinite Jest to survive a period of deep depression, denial, and directionlessness, so that shattered consciousness was pretty easy to relate to at the time.