Once again, by showing your cards, you will give your opponent more information about your game strategy, which poker tries to hide.
You can't be sure that a particular player isn't playing a hand just to find out the specifics of your game. Maybe he didn't get any clear information, and then you opened up and showed him everything for free. Original-it is to show only one card, which would cause the enemy to be confused and confused. In General, you need to show cards only if you have a clear goal, for example, to mislead your opponent, work on your image, influence the psychological state of the opponent, etc.