Comment by Sophira
> This seems like a truly unreasonable level of political skill for nearly any setting. We're talking about changing every endpoint in the Internet, including those which can no longer be upgraded. I struggle to think of any entity or set of entities which could plausibly do that.
Case in point: IPv6 adoption. There's no interoperability or negotiation between it and IPv4 (at least, not in any way that matters), which has led to the mess we're in today.
Many servers and clients support both ipv4 and ipv6. So, in a sense, there's a "negotiation" happening between client and server.