Firstly rejection has the obvious intrinsic effect on one’s confidence/mental health. If one is constantly rejected with no one to point to as a “success” then one can get desperate.

On the extrinsic side, something I never see talked about is the effect getting rejected in front of other women has on your future attempts. This is not as common nowadays since we’re online but still a thing to think about. If you’re at a club/bar you only have so many rejections before you “poison the well”. If you get rejected often enough for it to be noticeable than you’re just gonna be the desperate guy that no one wants. If you shoot your shot to a girl in a friend group, you’ve essentially closed off your chances with all her friends, so if she rejects you than you lose your opportunity with all of them.