Where do you get the idea they're the norm now? Have you some kind of evidence to back that up or is it anecdata because there was a loud child last time you popped into a supermarket?
If it! Kids on one side, shouting screaming non stop. Kids on the other side just as bad, be we ever hear apparent telling them to calm down.
Go to the gym, kids running into you, then starring at you, seeming unable to articulate a sorry. Door slams in your face. Taking a shower is a nightmare, kids screaming, singing at the top of their lungs, trying to look at you from under the dividing wall.
Kids in train who can't stand still, shouting, arguing, constant 'muuuuummmmm', and no regards at all for anyone around them.
You might see the best if them as a teacher being a figure of authority, but behaviour tolerance has certainly gone down with kids disturbance more and more considered something others have to tolerate.