To me my physical attraction to women is:
face > weight > length > waist/hip ratio > Breast shape > nipple shape > size of nipples/boobs > jiggle.

I’m not attracted to a woman that has the body of a regular rock,
lamppost or dishwasher or I’d be physically attracted to those things.
So the way your body looks is very important for physical male attraction,
but I would say that the bar currently is low for male attraction in general.

I don’t think breast shape is ever a deal breaker for the vast majority of men, at least not for me, but it does bring in attention.
They’re at chest level and can take up a good portion of the body,
so they’re quite difficult to ignore, especially if they’re large.

The right size is only a small bonus and the bigger they are, the more attention it brings.
Jiggle also brings more attention to them, but size is more important as it (falsely?) implies easier arousal.

They’re also soft, thus very kissable and there’s nipples on them that can indicate and entice arousal.