The administrative region with the nation's capital in it gets preferential treatment, pretty much universally across countries and times. DC sort of gets the opposite treatment, though, which is good from that perspective but sort of sucks for the people living there, since they have limited autonomy. So I'd posit that DC, the territory, should have no residents besides the President himself; the only way I get that without forcing seven hundred thousand people to move is to change ownership of the land to some state that wants it.

The same reason it doesn't make sense to make Denver or Seattle a state; stripped of the important Federal buildings DC has literally nothing remarkable going on about it. States need actual land and resources and all that other stuff such that you could vaguely see them operating as an actual nation. As it is it'll just end up being bullied by all the other states

Just avoid the border gore and force Maryland to take the extra land, tax income, and voting population; it'll probably be enough to knock them up a House representative or two anyway.

So Rhode Island shouldn't be a state? Wyoming? What are your requirements for being a State? Should NY or CA be 2 states? Why not?

States aren't allowed to secede, per Lincoln, so operating as a nation is irrelevant. (Texas is special.)

The original US required every state to have access to the ocean, so Colorado and Kansas shouldn't be states.

This is a remarkable statement, because more people live in DC than in Wyoming or Vermont, and the purpose of a state is to serve its people, not its buildings or "resources".

It’s poorly worded in the comment you are replying to but “make DC residents citizens of Maryland and Virginia instead of adding a state” is a cogent argument with lots of merit.

Of course those 2 senate seats that would certainly be Democratic make this a political non-starter.