It is dishonest to pretend that the mass exodus of priests, religious and laity occurred during th pontificates of St John Paul II and Benedict XVI. The walk-out began under Paul VI in the early 70’s immediately after the upheaval of Vatican II. St John Paul put a stop to the automatic laicisation of priests who wished to leave and get marrried in an attempt to stem the flow.
The “decimation of the faith in the traditional countries where the faith was strong” was well under way before St John Paul II succeeded to the papacy.