You can essentially create an LLC in Delaware (from anywhere in the country) as easily as you can create an Amazon account, so that's a big claim.
Anyway, the benefits go beyond how easy it is to open, the most important things are moving forward with things like stock options, issuing shares, creating preferred ones, etc, etc, taxes access to funding, etc..
It isn't a particularly worse arrangement with founders, and, again corporate law in Europe is really behind, making things like attracting talent for equity much more difficult.
You can also create a GmbH in Germany by downloading a few free templates from the internet and making an appointment with a notary. It's a bit more expensive than creating an LLC, but not significantly (maybe a few hundred dollars).
Especially since most of the cost come from running the business (tax filings, accountings, business registrations) and not the initial founding costs.
That's been one hurdle I've seen when trying to found a business outside your own country.
The other hurdle was requirements for local directors (New Zealand, Cayman Islands)
The states hasn't yet devolved into separate countries (I'm not sure what advantages California gets from the union. But a Brexit is clearly a costly move).