I get the problem with DC residents not having representation in Congress. It's a travesty of democracy. And the partisan in me likes the idea of adding two guaranteed Democratic senators.
I also get that DC has a larger population than one other state:
Vermont: 621,254
DC: 588,292
Wyoming: 522,830
That said, it would be weird to have a state essentially be a city, and a mid-sized one, at that. Is "weird" a reason to deny people the right of representation? Obviously not. But why then not make NYC its own state? Indeed, with a population of 8.3 million, it's larger than 39 other states. Same with Chicago, LA, Philadelphia, or whatever. Washington is only the 27th largest city in the US. Why should it enjoy more representation than any of those urban centers?
To me, the more obvious solution is to simply have DC annexed by either Maryland or Virginia. (Preferably Virginia, which would solidify it as a solid Blue state, and most of NOVA is a suburb of DC anyway.)
Can someone explain why that option is either ignored or a non-starter?