Too long penis = base girth is useless.
Let’s say that you with a girl and you have a penis of 8Nbpel, but the girl can just take ~7Npbel.
This means that last inch (base girth) is pretty useless. Base girth is very important to many women, it stimulates the clitoris and the clitoral walls.
For the most members base girth > mid girth.
So if we compare two dicks:
-8nbel x 6.0meg x 6.5beg
-7nbel x 6.0meg x 6.5beg
Inside a girl who can take a 7nbpel (which is pretty common), the 7” should feels larger because of the base girth.
The 8” should not be able to use his base girth.
What I want to say is that aiming for a too long penis (9”,10”..) is probably counterproductive and let us not use the thickest part of our penis.