Again, if you get a kernel exploit, you don't need access to the messaging app or to escalate privileges.
you're already root.
you can access any component without much restriction.
How the data is stored has nothing to do with this
you're already root.
you can access any component without much restriction.
How the data is stored has nothing to do with this
Pwning the app will only provide access to whatever permission it has and we are still sandboxed.
Pwning a kernel module\driver will provide access to everything whether its messaging, call logs, pictures etc. we are not sandboxed, we don't need an LPE exploit.
I think the priority is clear.