It's interesting that you bring up Pennsylvania - nearly every regulation, law, whatever that affects cities is either only enforced for "cities of the first class" or cities of the first class are specifically excluded. There's only one first class city in PA and I'll give you three guesses which one it is. So essentially you end up with three sets of laws - 1) applies to all Pennsylvanians and typically have nothing to do with cities or how they work 2) applies only to Philadelphia 3) doesn't apply to Philadelphia but applies everywhere else.
You're actually making a good argument in favor of jdasdf's point. Just try to get a concealed carry permit in Potter County, and one in Philadelphia County, and see how different they are. Both completely legal because there's totally different laws in play for the same process.
The premise was that big cities, like Philadelphia & PGH would somehow undemocratically impose their will on the rural parts of the state. Like you say, that isn't happening. Philadelphia's regulations aren't being imposed in Potter County.
You're actually making a good argument in favor of jdasdf's point. Just try to get a concealed carry permit in Potter County, and one in Philadelphia County, and see how different they are. Both completely legal because there's totally different laws in play for the same process.