Let me preface this by saying I am a man, and smoked a little too much, so I'm sitting here thinking... what is or was the original purpose of a bra? Weight support? Vanity? Covering the nips so people's eyes met your eyes and you can have a normal conversation? Like what's it all about?
Every woman will be different but according to my wife it’s mainly for the support. I appreciated this more when I had a testicular injury where I needed underwear that lifts holds and prevents unnecessary movement.
You didn’t ask, but I was wearing some jeans and somehow one of my ‘kids’ got stuck in a pant leg and as I yanked it off it became hyper extended and tore some ligaments.