I mean on a technical level. Are the devices that make up the infrastructure of the internet hardwired with IPv4? Is the firmware on these devices impossible to upgrade remotely?
If it’s just a matter of software or firmware then adoption should only take like a year but clearly that isn’t the case. So what specifically is stopping us?
The hardware and firmware supports it and we have inter protocol solutions to handle edge cases.
The problem is that when the Ipv4 addresses actually ran out, ICANN realized that a metric ton of them were in use because people, especially businesses, were not using NATing.
ICANN (ARIN) slowly grabbed the addresses back, and NATing became the standard so no one really cared that much anymore because the amount of public addresses actually needed was significantly reduced.
Other things like SPN, updates to SSL, and various other address sharing technologies reduced the need for individual public ipv4 addresses even further.
There’s still a shortage and a wait list to get new addresses, but it’s not critical so people don’t have that much of an incentive to switch to ipv6.