To me, the new noise pollution device is some of these heat pumps. I've camped near RV's with those and they are louder and more annoying than most any genny.
At the BalloonFiesta in Alb a couple years ago, where we are stacked in like cordwood next to each other, the gal next to me had a Honda genny in the bed of her truck and I could barely hear it at all.
But the sound out of some of the heat pumps on bigger RV's really carries. The trouble with them is also, those folks are running them in FHU parks.
Far as overall noise, I have camped pretty much every situation, and the quietest places are the over 55 parks. Us old folk are generally a quiet bunch !