Why is the Goldilocks zone considered a dynamic, moving target?

Answer

Because what was 'just right' last year might be perceived as too basic this year as customer expectations rise.

The optimal point is dynamic because contexts change; for example, in product development, rising customer expectations mean that a previously optimal feature set can become perceived as too basic over time.

Why is the Goldilocks zone considered a dynamic, moving target?
Balanceprincipleeffectcondition