Why does TreeSize not show system data on a mobile device?

Question / Problem

I scanned my mobile device, but TreeSize shows only small parts of the internal storage. The included storage card is shown correctly. Is there a way to show the complete internal storage?

Answer / Solution

TreeSize uses the MTP (Media Transfer Protocol) to access data on mobile devices. By now, MTP is the only generic way to access data on Android and IOS devices.

With MTP, the device itself keeps full control over which data are available and which are not. System files and other critical data usually remain hidden this way.