For example. In cyberpunk you are forced to first person in combat. That means to look around a corner you have to put yourself in danger. To mitigate this you can invest in certain cyber ware to see through walls or throw recon grenades. If you would be able to use third person you could just move your camera to look around an object. You would have to design the encounters with that in mind and the thinks like recon grenades or looking through walls get less interesting if you allow the view of the player to fly around without getting in danger. As you can guess I don't like this and consider it cheesing. Similar example for kingdom come. There are medieval helmets in the game where you can pull the front piece down. That will impair your field of View. But you get more protection. But this could just be cheesed by turning on third person.

This kind of stuff I mean by cheesed.