Are people fleeing churches or have they never been?
From 70% to 50% is such a large change in 20 years. For this to be caused by a change in _parenting only_ would mean that probably every child born 38 years ago until today never attended a church. (this data counts adults, so they would only start counting when they turned 18). That seems very unlikely.
https://news.gallup.com/poll/248837/church-membership-down-s...