There is a definite likelihood that acting out a belief will cause you to believe it due to your brain poorly distinguishing signalling and true beliefs.
That can be advantageous at times. Some beliefs may be less important to you, and worthy of being sacrificed for the greater good. If you say, believe that forcing people to wear suits is immoral and that veganism is immoral then it may be worth you sacrificing your belief in the unethical nature of suits so you can better stop people eating animals.
A willingness to do this is beneficial in most people who want to join organizations. They normally have a set of arbitrary rules on social conduct, dress, who to respect and who to respect less, how to deal with sickness and weakness, what media to watch, who to escalate issues to in the event of a conflict. If you don’t do this you’ll find it tricky gaining much power because people can spot people who fake these things.
D&D has often had issues with magic users. They often are stronger than non magic users at all levels. For example, use of the spell sleep allows you to disable a group of enemies with no save allowed. Exploitation is common.
In games you can generally gain a huge amount of power by researching the right choices and doing them.
In the real world that’s a lot trickier because people in the past have researched the right choices and heavily exploited and monopolized existing power resources, and any publicly known power resources will likely be heavily exploited. Competition makes it harder than when you’re playing with three or four people.