You know that's not what he meant. the world is always changing. it was designed in 1998 by networking gear companies, with their own company needs in mind. It wasn't engineered with end user, or even network administrators and app developers in mind.

The only reason it's around is because of sunken cost fallacy and people stuck in decades old tech-debt. A new protocol designed today will be different, much the same as how Rust is different than Ada. SD-WAN wasn't a thing in 1998, the cost of chips and the demand of mobile customers wasn't a thing. supply/demand economics have changed the very requirments behind the protocol.

Even concepts like source and destination addressing should be re-thought. The very concept of a network layer protocol that doesn't incorporate 0RTT encryption by default is ridiculous in 2026. Even protocols like ND, ARP, RA, DHCP and many more are insecure by default. Why is my device just trusting random claims that a neighbor has a specific address without authentication? Why is it connecting to a network (any! wired,wireless, why does it matter, this is a network layer concern) without authenticating the network's security and identity authority? I despise the corporatized term "zero trust" but this is what it means more or less.

People don't talk about security, trust, identity and more, because ipv6 was designed to save networking gear vendors money, and any new costly features better come with revenue streams like SD-WAN hosting by those same companies. There are lots and lots of new things a new layer-3 protocol could bring to the scene. But security aside, the main thing would be replacing numbered addressing with identity-based addressing.

It all comes down to how much money it costs the participants of the RFC committees. given how dependent the world is on this tech, I'm hoping governments intervene. It's sad that this is the tech we're passing to future generations. We'll be setting up colonies on mars, and troubleshooting addressing and security issues like it's 2005.