So, other than the Westernmost parts of Eastern Europe (which we can start including, since the EU has kickstarted their economic development dramatically), the US is by far the most religious country of any in what we might consider "The developed West".
But it hasn't experienced a lot of the same cultural changes that it's most significant allies have gone through. Why not? There's a number of other reasons: The Strong Link culture (ie optimize for the STRONGEST members of your society rather than the weakest) that is somewhat unique. The fact that it wasn't destroyed in WW2 is another (Though neither were Canada or Australia). The fact that it felt like it was "The Leader of The Free World" for the last 80 years (and therefore had no reason to introspect).
But I think the core of the disagreements within the US between the Left and the Right come down to easily 40-50% of the country fundamentally believes that there is a magical man in the sky who will reward them from being good (for a fairly regressive perception of good) with infinite blissful life after death. And this is what they fall back to when it comes to justifying white supremacy (in every extreme), the discrimination of the LGBTQ, immigrants, etc.
Before you get to any other matters of policy or values, this is a fairly fundamental hurdle to get past. You either believe in a magical sky monster based on faith, and consider this to be more important than anything else you might do in your finite earthly life, or you...don't. And Americans DO at a rate more than most.
Everything else flows from this. How can you even conceive of getting on the same page of what a sensible tax policy, an introspection of the culture of police, the segregation of the cities, or the crumbling education system when you can't get past a fundamental belief.
So the systems prevail. The GDP grows. And just like wars stimulate scientific progress, so does the knowledge that if you fail you will wind up dead in a ditch, inspires some great entrepreneurship and ideas. A lot of which continue to change the world.
Then people on this website and others wonder why the same parts of the country generating the highest GDP also have the most human misery on the streets. It's because it's the other side of the same coin.