Assuming that to be true, I would expect there to be localities within the US where laws differ so vastly that they resemble different countries when juxtaposed. Yet, I’ve traveled enough of the US that this would surprise me. (It would be very interesting to experience those two, though!)
I think the US shows itself to be pretty homogeneous, with some differences between the rural, suburban, and urban areas, but not much.
Go to Las Vegas and then a dry county in Kentucky and note what you're allowed to buy and what you're allowed to do on the streets.
I can smoke weed legally for recreational purposes where I am here. Where I grew up I'd be thrown in jail.
Texas has no zoning laws of any kind. You can build any kind of building for any purpose anywhere (I'm sure there's still restrictions, but there's no zones per se.)
States have wildly different speed limits on highways. Different levels of allowed alcohol.
This is just off the top of my head without googling, I'm sure there's probably even bigger examples as well.
I think the US shows itself to be pretty homogeneous, with some differences between the rural, suburban, and urban areas, but not much.