I'm 64 and I am in the same boat as millennials. Since I never watch live broadcast network television I have no idea what shows are on, much less which network produced them.
I watch the news, movies and series on Netflix and Amazon Prime, and some documentaries from various sources. I watched Lost on Netflix, but I can't tell you which network it was originally on. Sitcoms? Haven't watched one in over a decade because they're all the same, with only the characters and situations changed. I don't care for mysteries or cop shows. There's very little good sci-fi being produced nowadays.
The premiums (HBO, Showtime, Starz, etc) are producing much better series than ABC, NBC, or CBS. I liked True Blood, Black Sails, The Young Pope, Outlander, and now I'm into American Gods.