I see the house passed legislation to make DC a state. Those who are opposed say it is a constitutional matter, but the wording in the Constitution would require a court to decide if that was legit without an amendment. It refers to "Cession of particular States" meaning the states have to give up any claim to that region and "Acceptance of Congress" which means Congress gets to approve the formation. I don't see explicit language that prevents forming it into a state. So it will be up to the courts if the Senate passes it.
The vote in the house was perfectly split along party lines. So it is clear this is purely about the balance of power in Congress. DC is very Democratic politically, so strongly supported by the Democrats and strongly opposed by the Republicans. According to Ken Paxton, Texas Attorney General, if DC becomes a state "it will not join the others in equal standing" and "it will create a super-state that has privilege and primacy over all others" that will "harm Texas". Yeah, that seems a bit extreme.
Seems to me the taxation without representation issue is the only significant issue involved. It's as if we required Puerto Rico residents to pay taxes without being a state. But we don't.
If it requires a constitutional amendment, I would vote for it. But the US can't even support an ERA, so not much chance of that getting passed.