As paper material is often more long lasting and safer than digital, what do you decide to keep physical copies of?

I have a bookcase full of cook books.
They'll always be there, and none of them have a long made up personal story before the recipe. Pluse they're hand me down from my grandparents.

paper in very good conditions (temperature controlled enclosure, with little to no air exchange with open environment). Assuming a normal hdd lasts 10ish years, and you do something like 1 to 1 redundancies, you can store digital stuff for cheaper, and lighter. I am not saying all physical stuff is bad, but paper is not good, unless you use some re-enforced papers like cloth or plastic