Time, Money, & Risk
In the realm of Project Management, there exists a constrained relationship between schedule (time), quality (risk), and cost (money). You can usually exchange these resources for one-another - but there exists natural limits for each. You can’t freely pull up schedule and reduce risk. There’s a reason we call it ”buying back time” and ”buying down risk“.
You can only have so much shaded area in that tringle. Moving up one axis will inevitably cost you on another axis.