There are a bunch of methods to add files/content to the (file_)storage:
create_file_from_pathname(); from normal filesystem to storage
create_file_from_url(): from url to storage
create_file_from_string(): from variable to storage
create_file_from_storedfile(): from storage to storage
I think we need at least two functions doing the inverse:
create_pathname_from_file(): from storage to normal filesystem
create_string_from_file(): from storage to variable
So, some processes like backup/restore can copy files out from storage and make their work there. I think that doing everything in the storage would be far from optimal.
Note I don't like the function names. They are only an "example". Perhaps they should be "export_xxxx" or another thing.