said by cowboyro:I would highly doubt, we are talking about the Internet, not the US-net...
Cutting off IPv4 would essentially render old devices unusable, old servers would be put offline. There are still many devices that can't use IPv6 - I have seen a ton of small business VPN gateways that don't support it.
No one said anything about cutting off v4, but v4 address space eventually running out all together and CGNAT and so forth being added it'll be that much more painful than it already is and become considerably less useful.
Those devices in time will experience problems depending on their use. But that's expected. I won't cry a river over it. That's what comes from sticking with v4 in the long run.