DC is quite poor in terms of happiness.
Low Level Of Integration With Local Communities
In DC local communities do not integrate well. People are generally respectful to their neighbors that live very close to them but usually that is as far as it goes. Humans are tribal and are happier when living in communities that they are integrated with, but nothing in DC promotes this.
Work Is Unsatisfying
In DC the majority of people do not work for the greater good, nor does their work directly improve their own lives. Rather they work for a corporation that they have no care for beyond the salary they receive. Great work by them only makes the corporation wealthier but does little good beyond that. This is inherently unsatisfying since we are programmed to want to work towards a better future for ourselves and our communities. Options that do benefit people such as working for the government or a non-profit company do not pay well. As such pursing such a path conflicts with our selfish and natural desire to benefit ourselves.
The other option is starting a business which can in rare cases result in riches. Even so this work usually isn’t greatly benefiting the community. The reason for this is that poor, unemployed, the homeless, the neediest of our societies don’t have a lot of money to spend on the services that new entrepreneurs create. Making rich people richer or making middle classes people’s lives slightly more convenient isn’t a bad thing, but it won’t provide deep satisfaction to most people.
Poor Distribute Of Wealth Creates A Variety Of Problems
The non-wealthy are less happy when there is a large amount of wealth inequality. When you elevate certain people with extreme wealth, especially when the poor are struggling it promotes unhappiness.
We have evolved to be happy by excelling at our work whilst helping our community. DC is a very different model and promotes purely selfish behavior, without much focus on being in and improving a community.