Rather I would clearly differentiate the Capitol, from the area known as Washington DC, or any other adjustments that would allow the residents of the area to become a state and have proper representation in congress. There have been constitutional arguments in the past to block DC statehood. Moving the Capital would result in the entire infrastructure of the Federal government centered in DC being compelled to move with it. While the Capital can be located anywhere, I see no reason for it to move.

Don't get this question. Is there any reason to do this?

Moving the capital means picking a new host city to inherit the traffic, security zones, and lobbyist real estate. Which city do you nominate, and does it actually fix anything or just relocate the mess?