Registered just to post here. I really hate bras. I don't think there's anything lewd or vulgar about breasts. If someone does believe that, that's not my problem. And if there are nipples, big deal. Life will go on and men have nipples too. Also there are many men who have breasts bigger than mine and until they're all wearing bras I'm not going to worry.
My breasts really don't move that much in day to day life... If I'm going to be doing something like jumping jacks I'll put on a sportsbra but I will want to take it off asap. There's no extra sweat from going braless because it's not like there's any skin to skin contact.
I don't experience any "breast tenderness" during my period, though that's supposed tobe a thing.
In terms of modesty I don't feel like I'm being immodest or anything. When I do put on a bra, that's when i feel uncomfortable and like my breasts are on display because bras make them look bigger and also make them really stick out and create cleavage. For the office, I just make sure that either the fabric is thick enough or there's pockets in the front or I just wear an undershirt or tanktop. I also have some large size training bras that I wear when I absolutely must.
It makes sense to me that bras are not healthy and don't prevent sag but it's not like that makes that much of a difference to me. I'd rather have saggy breasts than wear bras all the time!