I like multiple different things in my cities.
At one end, you have Ptolus, which is a maximalist city setting, which hundreds of locations and NPCs detailed. But it makes it work through travel guide-style organization (think Lonely Planet or Fodor's), with a good use of a side rail, icons, color coding, etc., so that it rarely feels like a 600-page book. I've been using this as the basis of an ongoing fantasy campaign since 2006 and would be happy using it for the rest of my life. (Also, lifting up said book will likely help extend my life.)
On the other hand, I'm increasingly of the opinion that cities (and megadungeons and settings generally) can largely be run off of bespoke generators that help determine most contents of a region, including who's there, what they're doing, the aesthetics, etc. Most settings would still have some marquee locations that are fully detailed, but I probably don't need the dozens of taverns detailed in Ptolus to all be written up. There's maybe three or four of them in the source book that really merit that treatment. The rest can be generated on the fly and just put into campaign notes. Books like Into the Cess & Citadel (which creates a very specific type of hellish city) are good here.
I think city books generally fall between these two points on the spectrum, and creators and buyers all have different spots they like.
I don't regret owning and using Ptolus -- I wouldn't have replaced by 3E version with the 5E one if I did -- but otherwise, I'm much more interested in a lighter book where I'm not expected to adhere to the name of a baker's second daughter in a backwater alley of the city, unless she's killing people and putting them in pies, or something.