Just remember we got rid of TLS 1.0 the same thing can be done with IPv4. It's time for browser makers to put "deprecated technology" warnings on ipv4 sites.
IPv4 isn't depreciated, it's exhausted. It's still a key cornerstone of our current internet today.
We still have "modern" hardware being deployed with piss-poor IPv6 support (if any at all). Until that gets fixed, adoption rates will continue to be low. Adding warnings will only result in annoying people, not driving for improvement.
exhaustion probably also constitutes as "deprecated" once the utility of a system designed to be, well, useful no longer meets the usefulness quotient that it previously provided. Suddenly It's "deprecated technology"
genuine question, any reason not to just actually deprecate it then? Like just stop producing hardware that routes IPV4. Chances are there's enough that'll already do IPV4 it won't be a problem, and im sure if you really needed to, you could figure something out.