> Why is a shared entertainment media experience important?

Just some thoughts:

When I was younger and Lord of the Rings made a comback, most of my friends read the books in a hurry, discussed some big events, played with sticks and that was it. With Harry Potter we had to wait in between each book. We spent hours discussing the books, re-reading them looking for clues.

I can't really watch a series alone, I have to "share" the experience with someone.

Agreed. I find that merely experiencing it (books, movies, video games, any media) is enough to form some bond with people later on down the road. "Did you watch X?" conjures up memories and emotions, enough to start a conversation to add your own thoughts to "X", so why do you have to have, "Remember that time we all watched X?" instead?

We are social creatures who still sit around the campfire and discuss our shared experiences. What we shared has changed and where and what the campfire is has changed, but that is humanity. We connect over the common events in our lives to the point that we have events that whole generations remember, refer to, and sometimes measure time since.

It's a medium for social exchange when you have no other shared topics. Similar to how alcohol is social lubricant.

> it rarely says anything of import about the world

That's a pretty bold statement to make. Do you feel the same way about books? Movies? Stage plays? If you're trying to say that "[art] says nothing of import" I think many would passionately disagree.

If you're only talking about television... I still think you're wrong.