Because the numeric keypads are largely unused and not ergonomic (wrist travel distance from letters to mouse). They are the "tenkeyless" variety, which many prefer. You can find full 104-key mechanical keyboards if you want as well, or get an external numeric keypad.

Cynical answer: These things are expensive enough without adding another two dozen switches, and besides, Kids These Days grew up using laptops and don't get the point of having numpads when the numbers are all already there above the letters.

You can configure a layer to act as one, without adding more hardware and making the keyboard larger and less ergonomic.

Nuphy has one!