Serviced apartments in washington dc for a short stay, is 2 weeks enough or too much time there?

Taking an actual extended vacation this year and considering spending 2 weeks in dc rather than doing my usual shorter trips to multiple cities. Been there twice for a few days each time and feel like I've only scratched the surface.

The museums alone could take a week if I actually gave them real time. But I also wonder if the city gets repetitive after the tourist stuff runs out or if there's enough there to fill a longer stay. Anyone done an extended visit to dc as a pure vacation? Is it worth it or would 2 weeks feel like too much?