Why can’t I just give my old set to my kid?

A child’s body is growing and needs consistent and even support from their mattress, like the kind they would get from a new set from Lebeda. Additionally, over time, a mattress collects dead skin cells and hair follicles which attract dust mites and other organisms that when combined with all the body fluids that go into your bed on a nightly basis, leads to a rather unhealthy situation. And besides, if your old mattress isn’t good enough for you, why would it be good enough for your child?