FTA:

>Individual economies such as India, Viet Nam, and Saudi Arabia exhibit adoption curves that differ markedly from the global average. As the APNIC Labs data shows, this global trend does not necessarily reflect the experience of individual economies.

>APNIC’s own measurement records a 42% worldwide IPv6 capability (Figure 2). That’s a substantial difference, which also needs clarifying."

The nuance is that IPv6 is growing faster in developing countries with poorer economies. I'm guessing this is because building modern IPv6 network from scratch is cheaper & more efficient than acquiring scarce and expensive IPv4 addresses. This is a major advantage for newer providers in growing economies.

So while the Google is showing it at 50%, APNIC's weighted global measurement shows it at 42%.