> Personally I don't know whether this is a thing or not, but I've been hearing rumours about carrier-grade NAT and how it's going to be widely used by ISPs in the near future.
CGNAT is widely deployed, and customers typically have no clue it is in use, until of course things break and nobody can figure out what is going on. Every tech I've met has no idea why customer one has "public IP" 100.64.1.5 when customer two also has "public IP" 100.64.1.5 when they live in different states when they get allocated IP's out of RFC6598 space.
Of course I get brought in when everything is fubar. The ISPs doing CGNAT are doing heavy rate limiting to make sure their CGNAT gateways aren't overloaded, and doing dirty tricks like redirecting all speed test sites internal so they look like they have great speed, until of course you have to transit outside of their network and find that you have almost no bandwidth besides the tricked out ports the carriers play around with.
But IPv4 is "good enough", except when it isn't. IPv4 won't die until it is too painful to use. Too many techs are blind to the world outside what they know.