While Apple has largely moved on to standalone apps like Apple Music and Apple TV, iTunes 12.6.3 (and its minor successor, 12.6.5) remains relevant for specific niches:
This is the biggest hurdle.
People who preferred downloading a large app once on their PC and syncing it to multiple family devices. Why iTunes 12.6.3 Is Different itunes 12.6.3
For modern iPhones (iOS 13+), stick with the latest iTunes or the Finder (macOS Catalina+), as 12.6.3 lacks device drivers and security updates. While Apple has largely moved on to standalone
Users who want to save .ipa files of apps that might be removed from the App Store. Users who want to save
iTunes 12.6.3 is a "safety blanket" for power users. It represents the last time Apple prioritized over subscription .
Immediately following this release (starting with iTunes 12.7), Apple from iTunes, pushing all app management to the iOS device itself.