The first sentence as written is incomplete. Of course punishment changes behavior. This is well established through a long line of experiments going back to the 1940s or earlier. To complete the sentence, there should be a "permanently" added to it somewhere, since the association between the punishment and the behavior wears off over time.
The association between positive reinforcement and behavior also wears off over time, but that is easy to maintain by occasionally rewarding the good behavior. You don't have to reward it every time. You might reward frequently when trying to to teach the good behavior and then you can decrease the frequency.
I think a good way to think of reward and punishment is that reward encourages repeating the behavior that is rewarded, whereas punishment encourages not repeating the behavior that is being punished. When you punish a bad behavior, that doesn't necessarily lead toward good behavior. It could simply lead to different bad behavior.
That's not to say that there is no room for punishment of bad behavior. Rather, it should depend on how bad the behavior is. If the behavior is something that is very bad, in the sense that it seriously harms people or animals or causes major economic damage, then punishment might be appropriate. For instance, if you have a kid who has taken to lighting cats and dogs (or smaller children) on fire, then severe immediate punishment might be appropriate, to get that behavior to stop now. That gives you a window until the association between the bad behavior and the punishment wears off to try to reward enough good behavior that the kid won't have time to go back to the bad behavior later.