Your reply is flawed 1) People choose to live in the same city so they have that in common 2) 7B don't all interact together, thats not the point. The point i

Your reply is flawed 1) People choose to live in the same city so they have that in common 2) 7B don't all interact together, thats not the point. The point is that its random who you talk to as most social media is anonymous. Combine this and you have low trust + low chance of having similar viewpoints/culture/beliefs. Manage just fine does not mean everyone is happy, and in these major areas like NYC people always seem to congregate with the groups they share the most in commong with.