> When I came to the US in mid-90s (as an atheist) over half the population attended religious services regularly.

No. When polled, half the population said they attended religious services regularly.

Researchers going to churches and estimating attendance found actual attendance was always less than what polls said. If people actually attended services like they said they did in polls, pews would be much more full (now and before).

Also, you know two people, but I could give examples as well - a normal secular family doing well compared to some evangelical family which is not doing well at all.

Also - there are suburbs which have, say, a sizeable Norwegian population. People go to some ELCA church. You talk to them, and a lot of them don't believe in the tenets of Lutheranism - miracles, the resurrection of Jesus etc. But they go to weddings, funerals, services, coffee after services. Dinners, clothing drives. Events around Easter. For many of them there is no belief at all, they just have coffee with their neighbors every week. Technically they are considered Christians, without believing in Christianity per se.