I have a couple grails I am thinking of selling because I don’t think I would ever wear them and because I’m scared of them crumbling since I just keep them in my closet. Shoes include Kobe’s grinches, off white prestos, union 1s, fragment 3s. It’s been almost half a decade for some of these shoes and I heard wearing your shoes from time to time helps preserve the soles better since they prevent the material from crumbling.
Everything will break down after time. There was a video I saw a guy in Japan had an original Jordan 1, the shoe damn near discingrated. I believe the owner had the pair in a case to save what was left.