The Mormon Church has much higher compliance rates on tithing and gets a lot more out of its followers than Catholicism. They have Church-only welfare systems and other practical benefits conditional on membership, require spouses and family to turn their backs on those who leave, censor/forbid 'dangerous' information, have followers go on long missionary trips to make belief more of their identity, etc.

In general, I don't think you should view tithing in the face of strong Dark Side techniques as really voluntary charitable giving: people give more because of the pressure, and the religious organizations want to do visible 'good works' (other than paying priests and for temple construction) for recruiting and retention purposes.