Problem is you have to find an usher. Then the usher has to be willing to do something. Then the person and their friends have to be adult enough not to start

Problem is you have to find an usher. Then the usher has to be willing to do something. Then the person and their friends have to be adult enough not to start harassing you for it. And if they try to assault you, you need to be able to defend yourself and your date/friends. That's why most people do nothing and concerts get worse.