@NagatoVpain Wanda Maximoff is a bad example because she doesn't have immense cosmic power, she has immense magical power. Dont listen to that person up there, Wanda was just augmented by cosmic power, that did not allow her to warp reality, her Chaos Magic did.
Now for your question, yes, anyone with great cosmic power can manipulate reality because the ability known as Cosmic Manipulation has Reality Warping in it and also the fact that you can be powerful enough to manipulate the universal forces of the cosmos.