> folks plugged into a community live better, happier, and healthier lives

It is this mainly. Community is the reason most people find happiness. Some people find it at church, some on a Sunday at a football game, some at their dnd game that’s being going on for years and some find it in their family. I am not particularly religious but I am 100% onboard the idea that community brings happiness. I find happiness in just having good neighbors.

> There’s nothing causational about the denomination.

You're right, I'm sure the people that are publishing these studies have never heard of "correlation is not causation."

... or people who attend religious services are less likely to self-report depression because of perceived weakness, shame, etc