My experience is you are indeed correct. Modern phone/tablet users are so divorced from a file systems that those brought up on them have no idea what a file is or where their data is saved... The data (video, music, shopping-list) simply exists "in the app".
(And don't get me started on their concept of data portability!)
...I mean, we've spent the last decade building products with the explicit intention of hiding or otherwise papering over the File abstraction. The hell did anyone expect to happen as a result? People coming in or aging out lose the knowledge as part of context degradation. There was value in keeping it as a first order abstraction.