" the only way to unite the US again is to reduce the influence the federal government has on norms at the state level and community level"

I don't think this would unite the country at all. This would sow so much confusion and hamper the economy severely - ironically, the very reason a Federal government was needed in the first place. Prior to that, every state and province had such wildly different rules, standards, and even currency that it was extremely difficult to conduct trade.

A strong federal government is also necessary when negotiating with other countries, and important in defending the country's sovereignty. If states had so much freedom that they were all cutting different deals with different foreign powers and making their own trade deals, foreign actors would easily manipulate and exploit this to their own advantage.

There's also the issue of standards. Education is a good example. There needs to be a national (or federal) baseline of what a High School Diploma means (for example), and what a Bachelors Degree means. If states went so far in doing their own thing, it could be crippling to the cohesion of the country, as well as - once again - having severe implications for commerce. If employers have no idea if a degree from Georgia weighs the same as a degree from Maine, that's going to create a lot of confusion when hiring candidates.

Add to that all the standards and licensing and certifications enforced at the Federal level. This is necessary, or else you'd have the joke system of patchwork requirements we see with Concealed Carry Permits, where someone can go to a state where it is very easy to get a permit with very little training required (like Alabama), and then carry in a state that wishes to maintain much higher standards. This results in states banning or not recognizing other states licenses which is chaos. Citizens wishing to conceal carry in multiple states have to get multiple licensees.

Imagine if we actually got rid of the FAA. Would each state make up their own air traffic control procedures? Aircraft certification? Pilot licensing requirements? Would a plane licensed in Wisconsin and flown by a pilot trained in West Virginia be allowed to enter Colorado airspace?

I wonder if people who advocate an extreme form of states rights have actually thought any of this through. If you scale back the federal government so much that it is essentially powerless to enforce anything, then you cease to have a United States of America, but rather a mid-American continent with a patchwork of independent countries mostly doing their own thing... and warring with eachother. Like parts of Afrca.

Even Europe, which is still made up of independent countries recognizes the economic advantage of unifying under the EU, and facilitating free transit across the Schengen Area. Europe operates cohesively in many areas under standardized systems (like Eurocontrol for air traffic control), and the Euro currency.

Even in systems engineering, there's a basic principal that systems that lack strong orchestration and coordination and standard protocols will inevitably suck or not be viable at all. Even in decentralized systems (all the rage currently), there's still a need for standardized communication protocols, interfaces, and contracts. If you try to set up a data center where every server or node is doing its own thing willy-nilly, you don't have a data center. You have a bunch of individual nodes competing for resources and doing little else other than this as opposed to acting cohesively as one unit to actually accomplish meaningful work.

Corporations are another example. Military yet another. Try running a corporation or military where every unit makes up their own rules. Good luck.

I think 'states rights' has really just become a false battle cry for people who actually advocate for anarchy or some sort of anarcho-capitalist fantasy.