IPv6 migration has been dragging on for a decades now and there’s no end in sight for this migration to complete. Huge software companies like Amazon are buying even more IPv4 addresses to continue to support IPv4 users. Given the current stance of corporations and many governments it seems that Internet will forever be split into two protocols.
Worldwide 45% of Internet users are on IPv6. This number is quite low if you take into consideration the fact that IPv6 was created almost 3 decades ago.