Will someone tell me, what the hell is the point of wearing jeans with holes in them?

My 12 year old grand daughter was showing me her new duds her mom bought her for school. I will say I think she has good taste in clothes, her shirts and her t shirts are pretty cool. But she’s all pumped about these two pair of jeans, with holes in the knees. Don’t want to rain on her parade, she likes her Paw Paws opinion. So I had to oooh and aww to make her feel good, but inside I’m WTF? If this is some new fad, I guess I hadn’t noticed before. I don’t even recall my hippie generation girls wearing crap like that?