Why are people so obsessed with a women's virginity even today when we already know that virginity is a myth ?

Had a argument in class about virginity and hymen and just everything even our teacher said that virginity as defined by society is a myth as literally you can just break your hymen while riding a bike or even just doing day to day things and it regenerates but still this girl didn't believe it i don't understand why people today are so obsessed with virginity or even body count because does it really matter because until ik everything just goes back to normal even after you have had sex however many times because uterus is a muscle it can strech but also just shrink or contract and also relax so I don't understand why even today when we know so much about biology, people still think it makes a difference like you got men swearing up and down in social media about how it feels different is that just a placebo effect ?like what is a big deal i personally don't really care like i get it could be cause of STDs and shit but like you can just use protection or get tested before doing anything but they are not worried about that just obsessed with virginity and low body counts it all seems stupid to me