Back to this. IPv6 makes sense if you have more than a few hundred thousand endpoints and a large engineering staff to manage it all. It’s tons more complex and fiddly than IPv4, so if you have, say, three full-time network engineers for IPv4, if you put in IPv6 you’ll need around a dozen (or one me, but I am rare).

It then does in fact totally make sense! Since IPv4 will always be around and IPv6 is as mentioned vastly more complex and often poorly implemented in hardware, you’ve just increased the difficulty of managing your network 50-fold at least. But some other problems do in fact go away.

Which is why mobile providers use IPv6 — they have the large full-time networking staff to handle it and millions of endpoints which makes even poorly-designed IPv6 a sensible choice.

And all of the above is exactly why no one else should use it.