Only a small portion (relatively) of Internet-connected devices are currently using IPv6. We aren't likely to see mass-rollouts of IPv6 IPs for a while yet. ISPs are known for being ridiculously slow and tedious with any kind of service upgrades, and the process of updating all of your clients to IPv6 is a bit tougher than pressing a big red switch.
You said:
technically we've been using IPv6 and just not knowing.
Unless you were referring specifically to users with the "Unknown IP" issue (which wasn't clear in your post, hence my confusion), that is completely untrue.