I don't know about the USA being behind the curve, as they are on their own curve. What I see in the USA is a significant culture of "fake it until you make it". People pretending to be happy, wealthy, successful, spiritual, faithful, and so on, because appearance leads to the real thing. The actual mainstream acts of virtue signalling, you know. In many ways the Americans are exporting this culture, so are ahead of the curve. In other cultures, appearing to despair and struggle with how hard it is to believe in anything in religious teachings and how it all seems so hopeless and lacking meaning could be a way of signalling that someone is really serious about their religion, rather than the opposite. This can also be superficial.
Quite often, people think about things the wrong way to protect themselves. Take a classic question like, "if god is good and full of meaning, then why do so many meaningless bad things happen all the time?" An opinion might be that this question sounds childish because it is the sort of thing a child might ask. And therefore as an adult you have to push things like this to the side using whatever clever adult sounding methods you can because that is what a mature person would seem to do. But children are often more free to ask profound philosophical questions. If you cannot ask profound questions and treat them with the seriousness they deserve, then you cannot progress and really grow, but will be stunted, in a way. Even Jesus was claimed to have said that unless you learn to become like children, you can never enter heaven. So Christians who reject childish or immature questions are not only being superficial but are going against the most direct commands given to them by Christ.