@debtinflation was making a pragmatic argument: that modernity renders these granular state lines obsolete. My point is that the EU manages to keep chugging with all these little sovereign states of 5-10 million people managing their own healthcare and retirement systems

Maybe a US state is something legally different than an EU country, maybe not. I would say the two weren’t intended to be different, and whatever trends have produced such a difference were a mistake. Either way, that doesn’t address the practicality question.