Why are the system keys duplicated on the numeric keypad?

Question

Keyboard

Why have keyboards been doing this lewdness for decades?
Two identical duplicate keyboards next to each other
(picture from Wikipedia)

Answer 1

To make it convenient to play carmageddon2.

Answer 2

For convenience, obviously. And the digital block was not originally present on the keyboard.

Answer 3

At a minimum, it replaced the mouse when it was not there and it was possible to move the cursor diagonally more.

Answer 4

In Norton Commander (and analogues) it was very convenient to move the cursor using the right block (digital, with numpad disabled), because at the same time, it was very convenient to press Enter with the right little finger and navigate through the folders.