Hate to say it but going way back to the Catholic Church, they kept their power (along with the Crown) by keeping peasants woefully uneducated and the Priest being the sole gateway for confession, baptisms, funerals, and tithes....
Once the printing press came in Europe and people became more educated, well there comes Protestants...then the Catholic/Protestant beef, Age of Enlightenment and so on.
An educated person can deduce to believe or not to believe.
The difference ultimately is we can see the dirt religious leaders do via the internet.
Wasn't an option even 20 years ago...