In A New Hope, Admiral Motti says that the Death Star plans were stored on data-tapes.
“Don't try to frighten us with your sorcerer's ways, Lord Vader. Your sad devotion to that ancient religion has not helped you conjure up the stolen data-tapes”*
I always figured this was something that would just be conveniently ignored in future installments, but Rogue One doubles down on this by making it clear that the Scarif facility is storing the Death Star plans on a data-tape.
Given that holograms, droids, datapads, and other advanced electronics exist, why does the galaxy far, far away use such as primitive technology as data-tapes at all, especially for something as important as the Death Star plans (which can be transferred to whatever un-tapelike thing the rebels hand off to Leia)?
* Just realized that Motti’s really rubbing salt on the wound since the stolen data-tapes were almost certainly destroyed by the Death Star’s destruction of Scarif and Vader surely knows that.