Over time, I realized in pretty much all cities in the world except SF, the rich want a stratified class system. The rich class interacts only with the rich, the employee class interacts only with the employee class, and the only class mingling there is is when the rich want to show off some art or cars or something else. This is just downstream of medieval serf culture, nothing new about this. What ends up happening is the employee class develops a deep resentment of the rich class (you can see this rn in NYC) and all societal progress is pretty much halted. The rich class gets over this by avoiding the city entirely (all the nyc rich and even the employee class spend atleast 30% of their time outside of new york). Again, this is not new and this cycle has played out hundreds of time in history. SF takes a contrarian approach where the rich actively try to interact with the employee class and they try to make more people rich so everyone can be better off.