I agree. There are many selfish people out there. But they dont live in a vacuum. In a world where you have the repsonsibility for your surroundings, many people could rise to the occasion. Also, if a water pipe breaks in front of my home and you decide to vote against fixing it together, what do you think will happen to you, either when you need help or if I‘m vindictive, sooner?
We dont have anything to compare our living conditions to because we have never lived any different than now. We dont attempt to test self governed communities. What do you think why that is?
One hint that shows me that it works are coops. They work without central oversight because its not the oversight that makes us interact but our own intellect.