Their portability and verifiable nature make them a flexible and accessible way to recognize and communicate skills (Bowen & Thomas, 2014)
Even before they were actually portable, a key benefit was rooted in portability and verifiability (and, to what purpose: "flexible and accessible way to recognize and communicate skills"). That is the WHY. And that ethos has been lost (or never acquired) by too many. There could be opportunity to refocus and zoom way in on the why and the key benefits.