Psychologically, it is precisely the "harsh" comitment that makes it seems worthwhile. Having a relatively high bar to entry makes you feel like you are part of an elite that can truly give you something valuable and shape your life from top to bottom. Paradoxically, faith being too accomodating take the risk to lose adherents to those that are not as easy-going

That's not true, people would be extensively taught in history and biblical theology if they just asked their priests. They went to mass every week, in churches that quite often had decorations precisely about this subject, and priests were expected to be able to explain them in detail if anyone asked -otherwise that would have made them seem quite unlearnt.