The most common switching device is an NPN transistor and they operate by switching a load to ground (any load, lamp, coil, etc) Similarly with MOSFETs.
There are devices that are "high side" switches that switch to the positive rail but they are more expensive, less reliable and require more circuitry to drive them.
Down to price and reliability.
It is well known by seasoned techs that PNP transistors are the first ones you suspect if you have a weird issue with any electronics (not just pinball machines). NPN are far more robust and reliable.
ditto....LOW-side switching has always been preferable, it's easier to 'sink' current (NPN) instead of 'source' it (PNP).
