>>>Most people are cutting the cord and ditching cable because just about everything that's on cable is available on streaming. But my question is: if nobody uses something anymore, then why does it still exist?<<<
Nearly everything on cable is available streaming? Where? Let's say you want to watch "The Big Bang Theory." It's on your local independent TV station at 7 and 7:30 pm. Where does that stream? You want to watch it from TBS? There's no free streaming for that either.
I know that you can subscribe to services like Hulu, Roku, Apple, Disney. But they cost money. Add them up and they'll be the same or more than cable.
How about broadcast television? Some folks can get a clear picture over the air with a TV antenna. For them, that's great. All the regular broadcast channels and the diginets for free! But for many folks, it's hard to get a good signal. Your living room is on the first floor and it's not on the side of the house that faces the transmitter tower. So good luck with just a simple antenna on your wall.
Maybe your market has transmitter towers all over the region, so pointing the antenna one way gives you some signals. But you have to reposition it for other signals. There's a way to hook two antennas up together. But again, it's complicated.
Yes, some folks are cutting the cord as a way to economize. But they are going to have to put up with not getting many of the channels and shows they used to get.