Honestly, trying to compare standard of living between states is tough; between countries it’s even harder. First, standard of living is typically measured using gross domestic product (GDP) per capita. If you have significant wealth disparities that will tend to lead to a number which is…questionable. It certainly doesn’t relate to anything tied to an average citizens actual “standard of living”. Not to mention that a state is really big (except for Delaware or Rhode Island which are basically counties) - how a standard of living for a state which includes New York City or Huntsville actually relates to an actual state resident not living in those areas is debatable. (I’ll ignore the fact GDP as a measure of anything related to the real world is insane; there are so many issues with it the fact we lean on it as much as we do to assess the economy is astounding to me).
Having lived in both New York and Alabama, my general feel is they are more similar than the typical New Yorker would be willing to admit. In the US - as finance capitalism displaced manufacturing capitalism, wealth congregated in large cities and smaller towns and rural America has suffered. Mid-size cities saw wealth move to suburbs - Birmingham, AL or Rochester, NY are less-than-desirable, but both have some very wealthy suburbs. If we’re capable of being honest, there are huge swaths of the US that are now no-go zones - I’ve been unfortunate enough to drive through areas in both states that looked like Brazilian favellas.
The big takeaway though is people in the northeast really need to stop looking down on most of the rest of the country - it’s a provincial attitude that contributes to the divisiveness that permeates our culture today.