Every country is different. My Chinese colleagues get stunned by the fact that private citizens can own and operate small airplanes. One of them sheepishly asked "how long does it take you to gather all the necessary permits for one flight?" I said "I can fly from here to California without ever talking to anybody."
How much truly does the GA weigh on the entire ATC costs? Of the 9bln ATC cost, how much do our 100,000 turbo bugsmashers weigh in? Mind you, I don't enjoy getting flight followings and talking to big brother. I do that to not be a pest. If you say no public money should be spent on GA, then I'll find tons of venues where my taxes are spent on - which I don't care about and deem to be a total waste.
Good. Let's kill GA. And have all the people working in&around GA collect government welfare. That's why we can't have good things. To quote Sage from "The Boys" who said "I could cure cancer, reverse global warming, but what's the point? Humans are animals. And the lines at Voughtland are too long as it is."
https://the-boys.fandom.com/wiki/Sister_Sage