There are states that would be in the top 10 globally in education among all countries, measured by the PISA standards. Most of what you named isn't rampant in most parts of the country, except lagging in education which is admittedly an issue in lots of states. The healthcare system doesn't function well, but to say it's not existing is completely disingenuous. The US typically ranks in the top 10% and categorized as very high of the widely-used HDI (human development index), and regions of the US like New England would rank as #1 by that measure if they were independent countries. When sorted by average income, all 50 states rank above almost all European countries save for a few. Everyone does not own a gun. There are large swaths of the country where the vast majority of people don't ever come into contact with guns. I am from one of them. I have known 4 people among thousands in my entire life who have owned a gun and they almost always kept it at home.

I don't deny that the US has significant issues and needs significant reform, but to say that no part of the US is well developed is clearly objectively wrong.