I am not an expert in this area, but I do have four daughters, a wife, and once ran a huge women's health division. Bras serve several purposes, if they don't serve yours, then don't wear them.
1) Sports
"According to research from the University of Portsmouth’s Research Group in Breast Health in the U.K., exercising without proper support can lead to breast pain, sagging, and even lower athletic performance (1).
This is because breasts don’t contain any muscle. Instead, they rely solely on your skin and connective tissue, known as Cooper’s ligaments, for support. External support (aka your fave sports bra) helps keep everything protected and in place.
What makes a sports bra right for you depends on your breast size, the type of exercise you’re doing, and your personal preferences. It can take some time to find the one that works best for you, so we’re here to help make the search a little simpler."
Looks
Some women like how they look with a bra versus without especially as they age. Bras provide "lift" when aging muscles or the sheer size of breasts make that difficult. In some cases, including a mastectomy a women might wear a bra as a prosthetic.
Comfort
Some women find bras more comfortable others don't
Modesty
Some women are very self-conscious especially in the cold when their nipples are clearly highlighted under their blouses, shirts, etc. Other women enjoy wearing sheer blouses that show off their bodies without showing of their nipples.
Enhancement
This is more than just "looks", some women feel they breasts are too small and so wear "padded" bras to give their bodies more shape.
Sex
For some couples the process of removing the bra as part of foreplay can produce strong stimulus.
Wearing or not wearing a bra is a personal choice. There are plenty of reasons to wear a bra and others not to.
Now for a man's perspective... don't blame me if I stare when unconstrained breasts bounce up and down with movement or if your nipples are staring out on the word like a second set of eyes. And besides, women stare as much as men...
https://www.bing.com/videos/search?q=baywatch+staring+at+breasts+you+tube&docid=608046066888760171&mid=B2BFADEDE3409D3369BFB2BFADEDE3409D3369BF&view=detail&FORM=VIRE
https://www.businessinsider.com/new-research-proves-women-stare-at-each-others-boobs-just-as-much-as-men-2013-10
We try to be discreet, but don't be offended when we fail. I am not saying it is okay, just that the less animated your breasts are the less they draw attention.
