This is overstating it. In Europe you still have state sponsored churches which were shunned from the earliest days of the US (at least partially). The church attendance rate in some parts of Europe is still very high. Poland is 60%, Ireland is 50%, Italy is 30%. Those rates are very comparable to the most religious states in the US (Poland tops all but Utah).

https://en.wikipedia.org/wiki/Church_attendance

You also don't realize how a lot of church attendance in the US is mostly cultural/social. Not to mention, Europe isn't without flaw, so it's hard to "compare" anything objectively.

Echoing the person you are responding to: the OP's original point is more about the abandonment of some guiding framework for morality, not necessarily about religious institutions.

Sorry, I meant to say Western Europe, where Ireland is an outlier. And church attendance is VERY generational - the vast majority of attendees are over 50.

Western European morals and philosophy are no longer influenced or controlled by religious considerations. I wish I could say the same for Australia.

While Western Europe is far from perfect, it's also not a morality-free wasteland of depravation and selfishness. This is what happens if you abandon religious moral guidance: nothing.

First off, just a bit of a nitpick, but as I understand it the Evangelical/pentecostal side of Christianity is doing pretty well, or at least it's not suffering from its members literally dying off (far from it, in fact). That was also my experience from about five to ten years ago.

Second, I'd argue it's way to early to conclude that abandoning religious moral guidance is a success. At most it's an (unprecedented?) experiment that so far seems to work.