Is it the boiling of water or higher temperature that cooks food faster in a pressure cooker?

It is the higher temperature, not the boiling of water, that cooks food faster in a pressure cooker.

Water boils at 100 degrees Celsius (212 degrees Fahrenheit) at sea level. However, in a pressure cooker, the boiling point of water is raised due to the increased pressure inside the cooker. This increased pressure allows the water to reach a higher temperature before it boils, which in turn cooks food faster. The higher temperature also helps to break down food molecules more quickly, resulting in shorter cooking times.