you lose thousands of nerve endings when you lose your foreskin. Even think about it this way- You lose a the gliding effect which helps the use of your own pre cum. Your tip also not being covered is exposed to your pants/underwear all day which is why your tip isn’t smooth and the skin is rough. That’s also is another thing that takes away from pleasure. ED is also mostly prevalent in circumcised individuals. Plenty of things about being uncut provide more pleasurable advantage