India, Dec. 18 -- There is a warning for all trusted systems in India in Indigo's recent operational meltdown. Imagine a similar disruption in India's digital payments backbone - the Unified Payments Interface (UPI). If Indigo's cancelled flights caused inconvenience, a payments-system breakdown could bring everyday life to a stop: We pay for groceries, transport, utilities, school fees, tolls, even temple donations through a tap. Yet this marvel of digital inclusion sits on an uncomfortable foundation: More than 80% of UPI transactions today are routed through just two third-party apps.

This isn't just dominance, it is systemic dependency. And dependency at this scale comes with serious risks. The National Payments Corporation of India ...