Exclusively IPv6 without any transitional mechanisms would be difficult to succeed with.
However, there are network upstarts like Jio (India) which made huge v6 investments from day one which use 464xlat for subscribers to access v4-only resources.
Also every mobile phone network ever (with a handful of exceptions) is IPv6-only, with a slow translation layer to reach v4 sites. Your app or website literally runs faster if you use IPv6.
>Exclusively IPv6 without any transitional mechanisms would be difficult to succeed with.
That's my point; why is it still difficult? What exactly are the pain points for a fully commercialized native IPV6-only business, and why do we think it will be easier to maintain the status quo?