Or that perhaps the key to New York's success is dependent upon the existing government framework?

I doubt that. Singapore, Monaco and Luxembourg are doing just fine without the blessing of a big state.

I'm not so sure these are very good examples. Monaco is effectively a tiny gated community of France for the super rich that produces little-to-no goods or services. Luxembourg is heavily dependent on support and the existance of the EU (receiving approximately €3,000 per person, the highest in the entire EU). Singapore is probably the best example of a city-state succeeding outside the framework of a larger state, but the size of their public debt is a little frightening for such a small country - and would be slightly less so if it was within a larger body.

There are also Andorra, Lichtenstein and probably Macao and Hong Kong (They could be just fine without England and China).

Monaco and Luxembourg both are inside the EU and exist very much as a result of cooperation with France (and the Treaty of Utrecht). They both have ceremonial militaries only, and subsist by facilitating tax avoidance for the nearby elites.

Wouldn't that argument work in reverse too? How much autonomy does Vermont (lowest gdp) need anyway?