I have not seen a practical way to go IPv6-Only. If I made my DNS, Web, Chat, Time and other servers IPv6-Only I would only be able to access them from a few mobile networks, most VPS providers and a handful of ISP's. One might be tricked into thinking adoption is high, but the VPS and mobile providers really throw off the statistics. Mobile providers due to sheer numbers of clients and being late to the allocation game did not have much choice but to go IPv6 and set up IPv4 gateways/tunnels.
I could see doing IPv6+IPv4 in a corporation and terminate everything on load balancers, allowing anything behind the LB to be any combination of IPv4/IPv6. But IPv6 only? I don't see any big companies doing that in my lifetime.
My ISP obtained some IPv6 space but have not deployed it yet as they are still trying to decide how to subnet and bill for it so I currently have some static IPv4 addresses. I am on a tiny ISP, so tiny all their C-Levels phone numbers and email addresses are still in whois. Most of the US ISP's doing IPv6 also do IPv4 even if sometimes it is CG-Nat.
I could see doing IPv6+IPv4 in a corporation and terminate everything on load balancers, allowing anything behind the LB to be any combination of IPv4/IPv6. But IPv6 only? I don't see any big companies doing that in my lifetime.
My ISP obtained some IPv6 space but have not deployed it yet as they are still trying to decide how to subnet and bill for it so I currently have some static IPv4 addresses. I am on a tiny ISP, so tiny all their C-Levels phone numbers and email addresses are still in whois. Most of the US ISP's doing IPv6 also do IPv4 even if sometimes it is CG-Nat.