200 years ago in the U.S. regional banks printed their own currency. The constitution does not create a common US currency, although we have been operating as if it does.

Will a non-nation state be able to generate enough credibility to run their own currency that lasts a lifetime?

I don't know be I think it's interesting to watch.

And if they do, it may force central banks into a corner by limiting their ability to print money (i.e., lowering the value of your currency by printing money will cause people to move their money to the alternative currency, leaving you with inflation).