It’s so bad that my fiancée has some bras that say she’s a B cup and others that says she’s a D cup. In order to go bra shopping, you have to actually try them on to find out if they fit.
If I had to try on underwear to see if they fit, I might not bother with underwear at all!
This might go some ways to explaining why I’ve never known a woman who liked buying or wearing bras. I’m comfortable blaming the patriarchy, which can absolutely get fucked.