Poor people leaving a city increases the quality of life for (richer) people that remain? That's not the obvious result of gentrification. I didn't say cities s

Poor people leaving a city increases the quality of life for (richer) people that remain? That's not the obvious result of gentrification. I didn't say cities should optimise for quality of life, but quality of life should be an important consideration in the generation of policy. Other factors like cultural diversity also need to be taken into account, as well as mixing people with different income levels. I have found apartments in Berlin, for instance, that I was unable to rent because they had maximum income caps (and very low ones).