Ip4 sticks around because ANSI?
Wut
No, because of the practice of legacy hardware not being updated because of cost, so modern hardware has to be slaves for legacy systems. The cost to upgrade the entire internet backbone to gear that can handle IPV6 would likely exceed a trillion dollars. You can't just expect a 30 year old asic, or 16bit memory controller to hop along nicely with IPV6's judaism.
Internet2 was suppose to wholesale replace what we have now with IPv6 until they realized people and businesses were not going to shell out the collective trillions to pay for it. Remember back in the 00s they kept saying IPv4 addresses were running out so everyone got creative with private network space and told them to fuck off.
https://en.wikipedia.org/wiki/Private_network
Fun fact, Internet2 was supposed to set up with ID and licensing per user so 1) no anonymous usage and 2) mark of the beast shit to cut you off the second you said kike in public.
(((ietf))) loves to shit on NAT but the internet literally IS NAT. It requires NAT to be "internet", the word givs it away "internet, noun, network of networks" not "one global network where your identity is your MAC address and your IP has your MAC address embedded."
NAT exists. We have been building systems to bridge these gaps for years
I love NAT , (((IETF))) hates NAT.