@Madken65 I still don’t get why they are worn it they are that uncomfortable.
Because the alternatives can be worse. Especially for women with large breasts.
"Bouncing boobs" when we're doing any kind of exercise (the larger the boobs, the more likely that includes things like "walking") is painful at worst and really dang annoying at best. Bras are generally uncomfortable but at least they hold the girls in place, which prevents that.
There are always women who choose not to wear them anyway.