The vast majority of that ~%40 of internet traffic is in direct disagreement with said prophecy though. Mobile carriers like T-Mobile, Verizon, AT&T, Telstra, Deutsch Telekom, Orange, (...you get the idea) all used pure IPv6 backbones with NAT64 edges to role out mobile telecommunications without needing double/CG-NAT or boatloads of public IPv4. Each connection made via IPv6 is transparently 1 less NAT session out a public v4 address and the IPv6 design greatly optimized the way the mobile network cores were built out. This is what has driven the growth of IPv6 on the internet (as more users switch to mobile) rather than an explosion of wireline and business users making the switch.
Where pressure is still lacking is in "small" enterprise type case (like most businesses, regional health systems, local government facilities, and so on) where the difference isn't really that much vs networks with 100 million or more clients riding). Only when corps get to the size of e.g. Microsoft do they really start seeing similar value at the moment. Everyone else can scrape by just getting that small bit of IPv4 and forgetting about it for now.