[daenney]

I'm not really sure that kind of comparison makes much sense.

HTTP is a layer 7 protocol, IPv6 is layer 3. Rolling out a layer 3 change is an entirely different thing and requires not just the two parties using it to be adapted, but everything and everyone in between. That plus a general lack of a positive business case for v6 has meant tremendously slow adoption.

HTTP/2 support on the other hand has been quickly added to major browsers and with a number of big players like Google and social media providers supporting it those numbers would rise much more quickly. Cloudflare and similar providers would skew those metrics too since they can accept the connection over HTTP/2 from your client but still talk 1.X to the backends.