if the US of all places isn't a culturally christian environment I don't know what is

Has US Christianity always been like this or has it changed? It all feels very manipulative to me now and the morals / virtues seem to have fallen by the wayside.

it isn't, not in his sense anyway. The moderate, central and northern European mainline Protestantism that fostered democracy, education, an egalitarian social contract and temperance you if at all find now only in small pockets.

It's a huge mistake to confuse that kind of deep cultural Christianity with what has been politically ascendant for a long time now in the US. That older, European set of values is still much more alive in say Sweden, which despite an even higher per capita rate of billionaires would not produce Garry Tan or Bezos or Musk.