The title sums up my question, but to elaborate basically what I want to understand is why the Android designers want apps that need to work with shared data to use a Content Provider rather than just accessing the SQLite database directly?

The only reason I can think of is security because certain files can by accessed only be certain processes and in that way the Content Provider is the gatekeeper that ensures each app has the proper privileges before allowing read and/or write access to the database file. Is that the primary reason why ContentProvider was created?