Why go to Church?

We received a lot of snow here, about 0.5 m, 18 inches. I just came in from clearing the driveway for my neighbors, in their mid-80’s, so the wife could get out and go to church. It took me about 45 minutes. I was completely insulated in a snow suit, snow mobile boots, face mask, wearing eye and hearing protection so I had plenty of time to be alone with my thoughts.
She HAS to go. I “get it” and will never question her. She’s elderly. Her husband is sick. They were born and raised in this rural town and did not have the educational opportunities I was afforded. Why is she risking a fall on the ice or a car crash in the snow? Maybe it is a social thing and she wants to see friends. Maybe she believes it will cure the world’s ills. Maybe she feels she is cramming for her finals. But, it seems to me, a non-believer, the effort spent going out would be better invested by doing something else. Surely the omnipotent, all knowing deity can communicate with her without the trappings of the building 10 miles away.
Is going to Church/Temple / Mosque, etc. a form of Zahavi handicap (a costly behavior or physical feature that reliably indicates health)? Is there an evolutionary reason to go?
Would the resources used by going to Church (i.e. time, effort, fuel, money, etc.) be better spent doing “productive work”, e.g., clearing sidewalks, picking up trash, feeding the poor, offering rides for the infirm, shopping for elderly, teaching literacy or math skills, helping with taxes, etc.?
I cannot ask my neighbor, but I can ask you. Is Zahavi at play here?
I intentionally put this in Social to promote discussion.