> Cities are for doing stuff.

Cities are just large human settlements with high density and a (mostly synthetic/mental) boundary defining it's area.

One of the many parts mostly any city has are residential areas. Noise is absolutely not desired there, even if you think it is. What you seem to be talking about are public, business and industrial areas for example. Demographic development has people living there, sure. But mostly because it's cheap because of the noise and other environmental issues.

Cities have always been cacophonous. Moving to a city and then asking your neighbors to be quiet is like moving next to a farm and then asking them to stop making smells. There is much more quiet real estate in America than noisy real estate — don’t go to New York City and then ask your neighbors to tread lightly after 8pm on weekends because your baby is sleeping.

Thankfully despite your opinion New York does a good job of putting these noise complainers in their place. Unless the noise is beyond the pale or at hours between 10pm and 7am, complainers are told to GTFO most of the time. Somehow the city still remains a highly sought after place to live, half of it because all the whiners who need silence for realigning their chakras have decamped to Hastings-on-Hudson.