My final thoughts on this topic: iOS uses this “sandbox” approach to file storage, unlike its big brothers, eg Linux, Windows and Mac OS. All of the grownup OS’s allow the end user (practically) unrestricted access to the file system. In Windows, for example, if you want to delete system files, thereby blowing up your system, knock yourself out. You are an admin after all, whether you wanted to be or not. If you don’t save your work, well gee, that’s too bad.
The thinking behind obscuring the inner workings of iOS is (I’m assuming) is that end users need protection from their own ignorance. I see the sense in that. Most users are not system guys. It only becomes a problem when you also drill into users that they don’t need to worry about managing and protecting their data. The app ‘takes care of that” for you! I don’t deny responsibility for shooting myself in the foot here.. it’s just that after 30+ years of experience designing hardware and software I still stepped in the metaphorical dog shit and deleted (‘closed”) my project file, not something I would do intentionally, ever. Memory is cheap, (unlike in the bad old days), time is not. Would it not be cheap and simple to create a project file in the cloud giving the naive user a fallback in the event of such an accident? Because accidents will always happen and we can all use some protection. (This also raises the issue iOS’s lack of comprehensive system backups, which would also save your bacon in such circumstances. A whole other topic.)
Thanks to everyone who helped walk me through this. Your willingness to help makes it easier being a newbie.