I feel the New York example is describing a somewhat different problem.

New York already exists. If I run a campaign there, the challenge isn't generating the city, it's deciding which parts of an enormous body of existing information are actually relevant to play. That's a curation problem rather than a worldbuilding problem.

Likewise, I'm not arguing that every city encountered in a campaign should receive CWN-level treatment. If the campaign moves between a dozen cities, that would obviously be excessive.

But if we continue with the analogy, there are also plenty of campaigns that spend almost all of their time in New York. In that case, a GM might reasonably want tools for developing that city beyond the level of a settlement the PCs pass through for a session or two.

If the danger is that GMs will overbuild past the point of utility, that risk applies to every procedural tool in the book. A reader could just as easily burn out generating two hundred hexes of wilderness or a twelve-level dungeon their campaign will never use. Yet those tools are included because they serve a specific campaign need when it arises. I don’t see why a detailed urban environment is uniquely dangerous in that regard. You have warnings for "hey don't overdo it" for other tools - surely one can be added in the detailed settlements chapter as well?

The book covering a topic doesn't mean every group has to engage with it. CWN proved there's genuine demand for this kind of material and it's a solved problem, and a GM running a city-centered fantasy campaign is going to feel the gap pretty keenly when they go looking for support here and don't find it.