If anything, Russia and the U.S. are pretty similar in terms of regional and cultural tensions.
I think you're trying to point out actual points of cultural tension, which I'd argue are largely superficial and mostly political. But I think OP was trying to say that the US is culturally diverse based on geography. And I think OP is right, the culture of Atlanta is very different than the culture of NYC which is very different than the culture of San Francisco or LA.
Similarly the culture of Montana or Wyoming is very different than the culture of the rural south.
I grew up in what most people would consider the rural south (a small town in Kentucky), and even the difference between various regions in the south are pretty stark... Just take for example this article; Kentucky, know for their bourbon, and I grew up in a dry county (couldn't sell alcohol at all). Prohibition laws stuck around decades after federal prohibition ended for largely religious reasons.
Not really. I live in Moscow, and financially I have a very different life from someone in a small town. But in terms of the culture and people around, the difference is not that big.
Here's a random youtube vlog about a small russian town: https://www.youtube.com/watch?v=QOwW5wdIt_w It's on the opposite edge of the country, and yet, I would only be able to tell it apart from Moscow's residential neighbourhoods by how tall the buildings, built from the same panels, in the same design series, are.