Yes BatShite they are fucking uncomfortable IMO.
Bras for me are a massive feminist issue - connected to both sexism and ageism. The purpose of them is to harness the unruly ones as otherwise society deems them obscene, really, and to conform them to a height / shape that is deemed acceptable to society and current fashions.
Wearing a bra outside the house for most women is not a genuine choice. Realistically I could NOT go into work braless and feel in any way comfortable. It would be entirely unacceptable.
There is also the issue that so many men feel entitled to comment on our breasts from the age we start getting them, and how so many girls respond with starvation + baggy clothes / and these days binders are available. This is a result of the gross sexualisation of this body part. See also the massive hooha over breastfeeding in public.
So all these issues for women and girls, that start when we are so very young, and are only just in the last few years getting discussed more openly, we are now being exhorted to shut up about them again. People wear bras, references to body parts as girls or boys is exclusionary, and there are no experiences that are peculiar to girls / boys and therefore girls should absolutely not raise issues around how they are treated / what happens when their bodies start developing.