But the other apps simply aren't as full-featured as iTunes; they align more with Apple's interests as an appliance maker and content vendor (original iTunes preceded the iTunes Store by several years). TV.app preserves some power-user features, like Smart Playlists, while stripping out basics like "Show In Finder". But the one that really grinds my gears is the way audiobooks have been shoe-horned into Books.app, with any semblance of user sovereignty removed.
Example: few years ago, I was planning a road trip, and wanted to quickly filter down a shortlist of audiobooks: "Unread, Genre: Science Fiction, Length < 12 hrs". Not only does the UI offer no affordances for that: it doesn't even display audiobook length, let alone allow sorting by it! I had to dig to find where the files are stored (in `~/Library/Containers`, with gibberish file names), then write a Bash script to `ffprobe` the files and parse the results. When audiobooks were managed by iTunes, this would have been trivial.