The issue I am talking about is not really electron vs hole flow. It's actually about why the electron source ended up being used as the reference for almos tall circuits rather than the electron sink. However it draws in electron flow vs hole flow because it seems that was a determining factor into why the reference was chosen to be what it is (simply, that what was thought to be the sink was chosen to be the reference). Then electron vs hole flow does matter because if it directly plays into how things ended up and if it were actually chosen correctly then it would have beneficial implications for actual circuits.
It makes a difference when you consider all the effort that goes into making NMOS transistors work in a non-synchronous buck converter. If reference had been chosen to be the electron source then it using the NMOS would entail no extra gate drive requirements, none of the disadvantages of PMOS, and allow 100% duty cycle. Sure you could choose the electron sink to be the reference in your buck converter since it's technically arbitrary, but it's not much use when the regulator's controller, as well as everything it's supposed to power is using the electron source as the reference. And making it floating completely defeats the purpose.