The barrier of entry to becoming a state is currently too high, and the barrier to stopping to be a state is even higher.

You keep saying "in theory". If the practice -- as you seem to admit -- doesn't actually work, then what's the point defending the theory? It doesn't work in practice, so it's a bad idea.

> Arbitrary or not, States are sovereign things.

In practice that's not really true. The federal government has many, many levers it can use to get states to fall in line.

> (which are again separate entities)

In theory, but in practice, most states are highly dependent on a few very populous and productive ones, for economic and military protection.

Not to mention that the Feds control the purchasing power of the currency and international trade, so the states aren’t sovereign to do anything of consequence.

Hence in practice, this whole theory of states being sovereign goes out the window.