It would be my guess that more people have left the Church because of the divorce issue than for any other reason.
Although possible, that’s pretty hard to unwind in real life.
Noh, that's just wishful thinking on the part of RC's making them feel morally superior to everyone else.
Besides, there's no need to.
Just convince the RCC to give you an annulment, aka, church sanctioned divorce, and you're good to go.
So that speculation doesn't hold water.