they aren't the same because this formula is called different number of times depending on the private key. in simple terms imagine if the formula was this: x+1 and you always called it with the same x (like you do with the generator point). if you use it with x=5 and call it 3 times (private key equal to 3) you get 8 and if you call it 6 times (private key equal to 6) you get 11 and so on.