Of course variance in terms of culture, demographics, and industry in even small countries can be massive. My home city in Southern Brazil of almost 1 milliom population has less than 1% black population. Last time I visited for 2 weeks I didn’t see a single black person. This surprises some people because of the perception of Brazil and the fact they imported more slaves than any other country in the America’s.

So yes, I’m not claiming US is uniquely diverse. It’s just unusually large so it has large amounts of diversity due to geographic distance and total population + historic & current immigration.

However what I was trying to say by 50 different countries is that the laws can vary wildly from state to state. It is something that isn’t common in other countries. Of course there are other counties with strong federated systems where the provincial-level governments have strong autonomy (Germany and Switzerland come to mind) I think these types of countries are uncommon.

For example in Brazil no state regulates specific substances. That’s a power for the federal government. So if you buy a substance that’s legal in one state, you can safely bring it anywhere in Brazil. However in US this is not the case. I have the example of kratom, but Marijuana is another one.

This is what I was trying to say by 50 different countries. They aren’t actually countries but in some ways they have just as much if not more autonomy than countries, besides of course foreign policy decisions. But look at California for example. It’s economy is bigger than most countries in the world.