I think a lot of American Protestantism's problem is that Protestantism has never actually run America. If you look closely at the founding fathers' lives, the monuments they built, and the organizations they were part of, you will find a substantial number of them were Freemasons. Even those who were not outright masons still lived in a milieu strongly influenced by it's ideals and values. I think America is not a Protestant country at all, but rather a Masonic country with a lot of Protestants living in it.
This is not an isolated phenomenon either. 18th and 19th century republican movements(meant here in the broader sense of "republics yay!", not necessarily the Republican party) were either directly caused by Freemasons, or strongly influenced by Masonic ideas. Simon Bolivar was an outright Freemason. Freemasonry strongly influenced the French Revolution, the Decembrists were men exposed to Masonic ideas during the campaign against France, and there were multiple Italian and Spanish secret societies with Masonic ideas as well. Prior to the invention of Communism, if there was some kind of revolutionary movement going on, chances were it was inspired by Masonic ideas and possibly directly run by Freemasons.
What are the consequences of this? For one, Freemasonry is not a Christian ideology. Christians can join it, but it is a Deist belief structure based on Western Occultism and the broader structure of the Abrahamic religions. Anyone who believes in a "Supreme Being" is eligible to join, and the French strains of Freemasonry have removed even this requirement. This means that Christians, Deists, Jews, Muslims, Satanists, and anyone else who believes in some kind of "higher being" will be accepted. It was tolerated in Protestant countries because it piggybacked the Protestant desire to question established doctrine, and to be fair, freedom of religion and freedom of conscience are core tenets of the belief system. In the early years of America, this may have been an advantage for it, since it allowed people who were nominally different strains of Protestant to work with each other without squabbling over theology. It permitted immigration from Catholic countries because it genuinely believes in freedom of religion, that all religions have core essential truths to them, and that Freemasonry reveals and elaborates that truth. Their view of the various forms of Christianity is that they are essentially religions for normalfags. If you want to know how the universe is truly structured, you have to become a Freemason. So it doesn't really matter if the peasants are Protestants, Catholics, or some other religion, as long as social order is maintained. This view is strongly incompatible with the Catholic view of the universe, in which there is a known, correct doctrine. Catholic rulers are morally obligated to promote this doctrine and actively suppress any deviations from it because if the peasants are permitted to follow the wrong religion, it risks their normie souls going to hell, and part of the ruler's responsibilities are to protect their subjects, spiritually as well as temporally. Combine this outlook with the revolutionary tendencies of Freemasonry, and you will see why Catholic rulers reflexively suppress Freemasonry. Catholics are forbidden by the Church from joining it, and normie Catholics are encouraged to be hostile to it. Freemasonry for it's part actively enforces secularism every time it gains power. It won't usually ban Catholicism because that conflicts with it's belief in freedom of religion. However, it will do all it can to limit the political power of the Catholic Church and make it one of many religions rather than the state religion. It does the same with various Protestant strains as well.
There is another aspect of Freemasonry that is important, and I think closely related to the problems of the west. Remember how it is heavily derived from western occultism? Well, that means it was strongly influenced by Kabbalah, aka, Jewish occultism/mysticism. In addition to copying many of these ideas and thought patterns, it couches them in the metaphor that you are a literally a mason working to construct the Temple of Solomon. Protestantism has Judaizing tendencies to begin with, and I think large swaths of the ruling class larping as a Jewish stonemasons metaphorically building Solomon's Temple, only reinforced those tendencies in American culture. But wait, there's more! As part of it's freedom of religion ideals, Freemasonry was probably one of the first footholds of outright Jews in western power structures. Sure, the Catholic Church and broader secular society accepted racial Jews from the earliest days, however, they had to convert to Christianity and essentially cut themselves off from the Jewish community to join. Freemasonry on the other hand, was one of the first groups to accept outright, practicing Jews, and also pushed to free Jews from the existing social and political restraints imposed on them at the time. Again, I think this partly contributed to the broader acceptance of Jews in western society, and the more extreme expression of it in American society. This in turn led to the present situation where Jews have essentially taken over western leadership.
Tl;dr: Protestantism in particular, and Christianity in general was always powerless bs for the peasants to follow, as such, specific doctrines or discipline were unimportant to the ruling class. The religion/ideals that actually run America are a mix of Freemasonry and Judaism.