DC only has a delegate in the House of Representative who does not have a vote. No senators. If you make it a state it would have at least 1 rep in the house and of course 2 senators. There has been talk of DC becoming part of Maryland, but DC doesn’t seem to want that. Some info here: https://en.m.wikipedia.org/wiki/District_of_Columbia_voting_rights
DC does get to vote for President, unlike the US territories.
They could change DC to have a house vote. I think that could pass actually. How can the people not be represented? It’s illogical.
I don’t know how Maryland feels about absorbing DC. I’m from Maryland, but I don’t remember any conversation about Maryland’s thoughts on the matter. It would add to the Maryland SNAP burden and other social services I think. That could be worked out though. Not sure what other negatives Maryland might cite. Another Jelly mentioned having to add a star to the flag, I remember people talking about that when Puerto Rico was voting fir statehood years ago, but then PR voted it down so we didn’t have to worry about the flag.