It's not likely to happen, but I understand how it might improve some inefficiencies. States such as many in New England and states like Maryland and Delaware are awfully small. The farther West you go, the larger the states tend to be geographically. At a more local level, I would like for it to be easier for cities and metropolitan areas to merge functions and services across current boundaries for the same reasons.
In some of the largest states, there are groups who periodically want to secede from the rest of the state because they believe other parts of the state don't reflect local values. California and Texas seem to always have these groups. (I live in Texas and few years ago a small group in the Texas Panhandle wanted to have the panhandles of Texas and Oklahoma joined into a new state with Amarillo as the capital. Didn't like being told what to do by all those big city transplants from outside the state in DFW, Houston, and Austin, blah, blah..) That's not likely to happen either.