It is generational. I looked over the anniversary booklet of a Pastor of thirty years ago (spanning the "glory years" of WWII and just beyond) and found that there was generally only one person in each confirmation class who was still active in that congregation.
Christian training of the young needs to start at baptism.
No, I'd say it needs to begin pre-natal--as in Christian parenting classes (with Baptismal instruction) during pregnancy.
More like during marriage preparation.