how does a pressure cooker help in cooking food fast, when in reality what it does is increase the boiling point of water under pressure?

In a pressure cooker, food is cooked in a sealed container that does not allow air or steam to escape out. The boiling point of any substance is directly proportional to the pressure, therefore, the boiling point increases as the pressure inside the container increases. The pressure inside the container helps the liquid to reach a higher temperature before it starts boiling. The higher temperature causes the food to cook quickly than when it is cooked in an open-mouthed container.