High-income and low-income individuals often have very different retail service needs, so "gentrification" of an urban neighborhood often leads to old businesses being replaced by new ones rather than in benefits for existing business operators. The dollar store closes down, in other words, and gets replaced by the artisanal jam shop. Important exceptions are supermarkets and drugstores. CVS is one of the heartiest breeds of the urban retail ecology, able to survive in a vast array of environments. But then there's the case of the liquor store.
The liquor store is interesting because rich neighborhoods and poor neighborhoods alike want a liquor store. But your typical upscale liquor store is very different from your typical downscale liquor store. Eventually a neighborhood reaches a tipping point at which it makes sense for the liquor store proprietor to attempt to remake the business, but this can be hard to pull off.