Right. It's similar to Windows and Android experience. Thing is, for the latter, I don't want to "pin files I always want to keep available" - I want them to actually exist as files in the shared storage, so other apps can operate on them as if on regular files.
(Unfortunately, both mobile platforms themselves are actively fighting this approach, and instead encourage apps to keep data in private databases and never expose them as actual files.)
The problem on mobile is more that the other apps don’t get access to the general file system, and/or prefer to import the files anyway.
I get the pain point, but databases are a much better data model for multi-device, intermittently-connected sync. Filesystems just aren’t designed to be async and conflict-resolving.