Initially it was because I had exhausted all the series I was interested in. But now there are many seasons worth of content that....I'm probably not going to watch any time soon. Because my habits have changed. The time I spent on watching shows is now spent doing something else. A show has to be extremely good for me to bother watching it. (Like Mr Robot. What a great show).
I've started watching a few shows again. But now it is at the rate of 1-2 episodes per week across all shows. Rather than 2-3 episodes per day. And it is a bit...boring now.
I'm not typical, but the industry has to be aware that people can change their habits. And they won't necessarily change them back.
(So what do I do instead? I spend more time making stuff and reading / listening to audio books while making. In the last year I read / listened to somewhere between 55 and 65 books. Not counting technical or scientific books)