It takes relatively wealthy people (or at least big spenders) to make trendy upscale bars and restaurants work.

Museums, opera, symphony, most theater, etc. are kept alive by the philanthropy of the local rich.

High salaries are paid by rich VCs looking for return, or companies with more cash than they know how to handle commissioning prestige projects. (How many people at Google actually work on revenue generation? That doesn't happen at Joe's Computers in Nowheresville).

Concentrated wealth is the reason cities can have these things.