States are also drawn to serve the drawer. Why do we have a North Dakota and a South Dakota? It's not because we had a North Dakota Territory and a South Dakota Territory; it was because they would enter the Union as solidly Republican states, cementing Republican dominance in the Senate and in the Presidency, and admitting two states instead of one doubles the effect.

There's no particular reason to treat the current boundaries as holy writ.

There is a reason, which is that regardless of how and why states were created, they are legally sovereign entities with their own separate governments.

A bunch of countries in the world were drawn on a map with boundaries set by the UN or the British. That doesn’t make them any less sovereign entities.