TV viewership in hours per week is pretty stable because as boomers retire and become disabled and unable to do anything else, they watch more TV. Young people, like under 50, are turning away from TV.
Generation X and younger people have been falling out of love with TV for a long time. In my case I remember sharply losing interest in TV around the 1990s. Even around 2000 I felt insulted by advertising that is aimed at people who don't have money -- only medicare benefits they can spend and the hope that they can hire a ambulance chasing lawyer to make a big killing.
TV for kids just sucks these days. The audience isn't kids, it's grandparents who imagine that their grandkids will be entertained by it.
Some day the last television viewer will die and the cable companies and networks will turn off the lights. Much like the music industry, the TV industry has been losing it's audience for a long time, and one day they will wake up and realize that their frog has been boiled -- and find somebody else to blame.