You never see everything.
Time and diligence budget are finite. Paying to investigate one thing means not investigating another, and the facts you skip still shape what happens.
You will have to commit before you are certain.
Procurement simulations where the information is incomplete, the stakeholders disagree, and every decision costs you something you cannot get back.
People react to what you did.
Four stakeholders with their own pressures respond to your actual decisions, not to a script. They will not tell you whether you were right.
Round two shows up in round six.
Consequences surface later in the run and the debrief traces each one back to the decision that caused it.