But yes, everything in D.C., even for 30 or 40 miles outside of the city, is absolutely consumed by the Federal government.
The downtown of D.C. proper, outside of the tourist areas, is almost entirely composed of foundations and think tanks and non-government organizations who's mission in life is to try and influence executive or legislative policy decisions. There's almost no other real industry by comparison. The tech scene in D.C. is dominated by fed contracting megacorps and small tech businesses that exist only to partner with those companies in order to get the small business set asides. The non-Fed tech sector in D.C. is abysmally small. It exists, and there are hacker meetups and proper commercial companies here, but the ecosystem for those companies is pretty sparse. Most of the non-fed commercial tech companies you find are IT services companies that help build internal infrastructure for non-tech companies.
D.C., the city, also dies after working hours and on weekends. There's minimal night life. It's slowly changing, but nearly everybody who works in the city in the Fed space, lives outside of the city. It means commuting here and traffic is easily as bad as L.A. It's so bad that many of the Agencies are moving or opening very large satellite offices 20 miles or more from D.C. just so they can find qualified workers.
The really powerful people, people sitting on all three legs of the tripod, don't live in D.C. at all. They'll live in Northern Virginia or Southern Maryland. If you want to bang into a Senator or a cabinet secretary while grocery shopping, go shopping in McLean or Great Falls.
It doesn't help that the residential parts of D.C. are rather grim and not very pretty. Even the old historic row houses are rather gritty looking piles of old bricks with broken sidewalks outside and overgrown weeds and grass everywhere.
But I think it's also that the atmosphere in the city is so stifling, the constant ladder climbing and political backstabbery so intense, that people just want to get away from it.
Take a look at the large West Coast tech companies with offices in and near D.C. and you'll see that, down to the position, they all open up their offices to cater to the Fed space. Amazon, Microsoft, Apple, Oracle, Google, etc. all have offices near D.C. and if you check out the job listings all require clearances and/or experience doing business with the Federal government.
Practically, nobody cares about how much money you make, or your investment abilities in D.C. It's your positional authority, and what that means, earned through the tripod of power, that people care about.