Denver would be a good spot for the capital. It's a beautiful city and would a lot more central than DC. The current capital is quickly becoming farther and father from the center of population which makes it harder and harder for the average American to visit it.
It is far easier to arrange a trip from Honolulu to DC today than from Atlanta to DC in 1800. Possibly 1900.
Especially because Atlanta was not yet a thing in 1800. But your point is apt. Location matters very little today, so long as it's not a remote Alaskan bushtown.
