Movies have a unique longevity because of how easily they can be transfered from generation to generation. Think of the animated movies for Robin Hood, Jungle Book, 101 Dalmatians, etc. You know them, right? They're older movies, that it only takes two hours to familiarize yourself with. They're not even really "classics" compared to other Disney films of that generation. But, because the time investment is minimal and they're accessible to kids, it's easy for them to transcend. And they do. That's extends beyond animated films. Ghostbusters, Jaws, Star Wars even ET continue their relevance because it only takes two hours to figure out if you like it in its entirety.
Now, what was the number 1 TV show of 1961 (the year 101 Dalmatians)? Or '67 or '73?
They were "Wagon Train" ('61), "Andy Griffith" ('67), and "All in the Family ('73). The only reason two of those shows remained "relevant" is because of syndication. But while the animated movies linger, the TV shows putter out into obscurity. A big reason for that is because it takes a much bigger time investment.
What was the top rated TV show five years ago (not football)? It was a tie between Big Bang Theory and NCIS. The top new show? Empire. Are any of those shows something most people would go out of their way to watch now? Top three movies in the US?
American Sniper, Hunger Games: Mockingjay Part 1, & Guardians of the Galaxy. I watched two of those last weekend.