Prayers be it Hindu prayers, Islamic prayers or Christian prayers are not beneficial. There are no advantages of praying. No one achieved anything through prayers.
Buddhism provides the most logical answer when it comes to prayers. Lord Buddha told that you are responsible for your own actions. Karma is also responsible for your ultimate fate. You will do good in exams if you study and if your karma supports it, you will become rich if you are smart and hard working and if your karma supports it.
Also Hindus/Islam/Christians believes that God removes a person's sins if he prays regularly which is again harmful as it would encourage more violence.
Hindus, Christians, Muslims have extremist elements because of such hardcore ideas like praying. RSS, Shiv Sena, Bajrang dal, Al qaeda, Taliban, ISIS, Crusaders, KKK are examples how strict religious beliefs can make a person animal like.
Meanwhile Buddhism did not have a history of promoting wars, slavery and rape. Buddhism is the most peaceful, logical and humane religion in this entire planet.