You may have lots of money - but does it make you happy ? Or does too much money just encourage greed and wasteful spending on things you don't really need, use once or twice and then put away in some cupboard. You can be rich but miserable, or poor but happy. "Money can't buy me love" (Beatles).
As others say - there is no simple answer to the question. For basic living needs - home, food, etc., - you need more wages /salary to be "rich" in somewhere like London than in places with less unaffordable housing.