The box outlasting the present is a familiar joke with a straightforward explanation. What holds a toddler's attention is the number of things an object can be made to do.
Objects are judged by what they permit
Young children explore objects by testing what actions are possible with them. Interest is sustained while new possibilities remain and fades once the object's repertoire is exhausted.
A toy designed for one action delivers that action reliably and then has nothing further to offer. The design quality is irrelevant to how long it holds attention.
A box supports climbing into, hiding under, pushing, filling, emptying, stacking and being drawn on. Each is a different investigation, and none of them was specified by a designer.
Feedback that is automatic ends the investigation
A toy that lights up when a button is pressed answers the question immediately and identically every time. The relationship between action and result is fully mapped within minutes.
Objects that respond according to physics keep producing new results. A box behaves differently when empty, loaded, on carpet or on a hard floor, and each variation is information.
This is why battery-powered toys often see intense brief use and then abandonment. The engagement was real and the material ran out.
Ambiguity is what allows pretend use
A highly detailed toy specifies what it is. A fire engine with sirens and livery is difficult to use as anything other than a fire engine.
An ambiguous object can be assigned any identity, which is the raw material for pretend play. The child supplies the meaning rather than receiving it.
Because the assignment can change, the same object supports different games across weeks. A box that was a boat becomes a shop without needing to be anything in particular.
Scale explains part of the appeal
A large box is one of very few objects in a home sized to a toddler's body rather than an adult's. Getting inside something is not otherwise available to them.
Enclosed spaces also offer a degree of control that small children rarely have. A space with a defined boundary can be occupied, defended and left on the child's own terms.
This is why the appeal survives the novelty period. The box is doing something structural that the surrounding environment does not.
What this implies about buying toys
The observation is not that toys are pointless. It is that engagement duration correlates with openness rather than with price, complexity or apparent educational intent.
Rotation extends the life of any collection. Objects removed for a period return with much of their original interest because the repertoire has been forgotten.
Loose materials tend to outlast defined ones for the same reason a box does. What is being bought is the range of possible actions, not the object.