Why can't the phone see the contents of the PC's memory?

Question

Android

For example, when we connect a phone and a PC using USB, we can see the contents of the phone's memory on the computer. Is it possible to see the contents of the computer hard drive through the phone?

Answer 1

When you connect your phone to a PC, the device becomes the PC client of the phone. The phone has a hardware-software USB client function through which memory access is organized.
Also, some phones implement the USB host function (HID), through which other devices can be connected to it.
In the PC, only HID is mainly implemented, although at one time there were USB-A to USB-A cables that allow you to establish a data / file transfer channel between two PCs via USB

Answer 2

Through a standard network service - FTP / SMB - easily.