As a machinist, I used quality tools my whole working life, and the ones I bought during my apprenticeship were still as good when I retired this month as they were when I bought them more than 30 years ago. That said, they mostly don't look unused, but all are still in perfect working order. I used them with respect and took good care of them, but I didn't baby them.
I feel the same way about my cookbooks. They aren't works of art, they are tools to be used. As such, they are stored in the kitchen because that's where
they are used. And they ARE used (not abused), but that means that they show the amount of wear and tear commensurate with the amount of use that each one receives. If one looks brand new, it probably means that I received it as a gift and haven't yet found anything that I wanted to make from it... or didn't really care enough for the recipes that I read in it to bother with trying to make any of them. But I still can't convince myself to get rid of those that I don't use... there is always someday.......