Please note the OP references the US not the globe.

Christianity is and has always been a religion that thrives under oppression & suppression.

In the Far East, particularly China, as well as in Africa & South America Christianity is doing extraordinarily well.

The problem with prosperity like we have here is that we (mankind) worship the gifts rather than the giver. This is the pattern you see throughout the OT as Israel is blessed by God then turns away, is punished for her unfaithfulness, and is once again blessed by God so in desperation turns back.

We’re in a trough while in other nations Christian’s’ suffering is just the way it’s always been.

We have new religions (Baals) cropping up like DEI SJW LBTQ-Infinity self definition movements that have claimed our allegiance.

It’s just a natural cycle that shows how unfaithful men are, and how faithful to His promises God is.