Why does tv and movies always portray small breasts as undesirable and less attractive?

I’ve struggled with body dysmorphia since I was about 11 or so. My main focus has always been on my breast size. I’ve been taught my entire life the small breasts are unattractive. My first memories of this are my mom complaining how flat she is and how much of a boy she looks like cause she didn’t have boobs. This obviously effected the way I looked at myself later on because now as a young child I’m embedded to think that having small boobs is a negative thing. All shows I’ve watched as always praised bigger boobs and all the women plastered on magazines have always had a lot of cleavage.

It just makes me feel really awful about myself. The more I see the culture be like the the more it instills a hate towards my body. I imagine alot of women feel this way so I just wanted to open a discussion about it