Why is it better to tenderize meat in a pressure cooker than in ordinary cooking pot

In a pressure cooker, the meat will be softer because of the high pressure which allows a higher temperature of cooking and will be ready more quickly.

A normal pressure cooker or any type of pressure cooker has a tightly fitted lid. This prevents any liquid or steam to escape, therefore the steam produced from the small amount of water in the pot is used to heat the meat. As the pressure increases in the pot this causes the temperature to rise. Such heat is used to break the connective tissue which binds the protein linkages together. This assist in softening the meat.

To elucidate: In a pressure cooker, due to the high pressure, the boiling point of water increases to 122 Celsius which is how it allows hotter cooking.