Thanks for your suggestion. There’s already an existing suggestion thread discussing an option to have movies and shows combined in a single library. I suggest you comment/vote in that thread in order to help us avoid distracting or cannibalizing votes. Unless I’m missing some unique aspect of your suggestion I’ll close this thread as a duplicate.
As a related suggestion… you can assign content from different libraries to same-named collections. Then the collection items will show up as related content (e.g. movies/shows/albums related to Star Wars).