Andy:
Your comment about "natural" transistors is "nonsense". NPN transistors, as discrete components on circuit boards are just used in more prevalence because of the era of bipolar logic, with logic levels biased toward the GND rail, made them more convenient to utilize.

As Charles has shown, there are a multitude of circuits, where PNP transistors and their counterparts the P-channel MOSFET are "the only way to fly".

Michael Karas