In the real world, it's impossible to de-risk new ventures properly.

This problem affects every stage gate step, including all launches until scale.

On the one hand, the "pull" factor of remaining showstopper assumptions means that teams should often de-risk more. On the other hand, the "push" factors of competitor action and lacking stakeholder patience mean they have to move on anyway.

In the end, when to move on is an imperfect and subjective leadership decision.