Why a filesystem (1/2)

Usually, the applications needs to save some data
Parameters
Calibration
Possibly log files

Defining magic offsets in flash only lasts so far
After a few items you get lost
You can't trade maintainability for laziness

Whatever your storage method, always include a version
If the "storage version" in the app mismatches, you must reset the storage
The filesystem layout will change over time
And the application format new devices anyways

This is different from the typical FS use in bigger systems