I know and like multiple people who have developed city builders, so I'm not saying you're bad for making or liking them. I just have multiple points of frustration.
I think it all started with the first SimCity game, a game based on US cities, as illustrated by the fact that the developers had to elide all the parking lots to make the game look remotely non-awful. And as cities go, US cities are weird. They're huge sprawling two-dimensional colonial things with barely any history.
Most cities have deep, convoluted histories: they almost always evolve out of earlier versions, growing and shrinking, being half-destroyed and rebuilt in different shapes. Think of Troy with its ten different layers.
Nor can you just treat a city as self-contained. They developed in specific places for specific reasons: on top of hills and in river bends for defensibility, on coasts and river sides and road crossings for transport, near important resources. A simulation of a city that does not take into account why it actually formed, that puts it into a nice square map where the geography is mostly aesthetic, is woefully incomplete.
So we build on top of what we've already built, again and again, with no overall plan. Cities grow as the result of thousands or millions of decisions. There isn't - can't be, given the time scales - a single driving will that shapes a city. They will always be messy and hence interesting. There can be no totalitarian overall plan for how a city functions, no matter how much certain people have tried.
To summarise: cities have history, geography, context, and they are grown, not designed.
So playing another game where you start out with an empty plot of land and decide where the lumber mill goes and where the dwellings go, as if that was centrally decided, decided once - that feels just too hollow. And this idea of empty land is colonial. There hasn't been truly empty useable land at least the neolithic. You're either building on what's already there, or you're lying about emptiness - "terra nullius" - because you're a colonizer.
Now could I develop this rant into a game design, make a game which fixes all those problems? I'm not sure. Placing the city in a flat or easily modifiiable environment, with no history or context, and with detailed control is what makes these games tractable and gives players agency. I'd love to see a game where you shepherd a growing, living, old city, rather than another colonial fantasy - but I'm not sure it would even count as a city builder anymore, and I'm not sure it would sell.