The empty box may entertain a child longer than the purchase it protected.

A box does nothing, which is precisely what makes it useful to a child. The toy inside arrives with instructions about what it is; the box is a boat, a house, a hiding place, and it changes according to whoever is holding it. Play prefers material to finish. Something that is not yet anything leaves room for the part a child actually enjoys, which is deciding.

Watch what a child in your life returns to rather than what they were given. Leave a few open-ended things about: paper, blankets, containers, nothing with a right answer. Notice where the same appetite exists in you.