That's a different concern though - Promoting the whole use case of the internet vs migration from one protocol to another.

If we compare the http to https migration, Firesheep in 2010 demonstrated that maybe migration was the right thing to do rather than just an optional security feature for banks, Lets Encrypt was released to the public in 2014 and by like... 2019 basically all of the internet was HTTPS. There is a long tail to go for the last few sites, and some that have objections to the CA system and are holding out, but really https is just expected these days, which is a much better place than IPv6.

Introducing HTTPS to existing infrastructures is easy. Just terminate it at some point. It also adds a big advantage to users that their traffic can't be read by network operators. Introducing ipv6 is harder, as you need to change all your routing, logging, banning, etc. facilities to support ipv6. It doesn't add any direct advantages for users, as all ISPs still have to support ipv4.

> Lets Encrypt was released to the public in 2014 and by like... 2019 basically all of the internet was HTTPS

Google's ranking bonus had also been a great incentive.

> Lets Encrypt was released to the public in 2014 and by like... 2019 basically all of the internet was HTTPS.

This is apples and oranges: absolutely zero software upgrades needed to be done to get HTTPS going and/or Let's Encrypt running.

I was able to get LE going on our F5 appliances in a few working days with zero changes to the base system/appliance software by simply installing the dehydrated ACME client and all of a sudden dozens of sites where we previously didn't want to pay for a cert were "secure".

Network hardware can stay in place for quite a while. Our previous generation of core switches lasted us 7 years before we swapped them out.

I wouldn't be surprised some of the mega-chassis routers in ISPs and other telcos sit around as long.

7 years for a core router is on the low end aswell. High end routers consist of a chassis which can last a decade or more easily. usually the line cards inside the chassis are replaced to allow higher band with, but the control plane can stay in place for a very long time.

So it took 15 years to build the entire Internet from scratch but it's taking over 20 years to upgrade to a new version.

It is a lot bigger now. I wonder how much IPv6 growth is net new hardware vs replacing old hardware

Easy, India vs USA stats show that. India had an internet boom after exhaustion so its adoption is new hardware. USA's boom predates IPv6 so its mostly replaced.

India's visible adoption stats are over-represented by lte deployment. Lots of broadband providers still don't have ipv6 and some major ones deployed it very recently.

Lots of IPv6 growth is by new ISPs that don't have the IPv4 resources that legacy ISPs have, like Reliance Jio in India.

Yep. Think about how long it took to get the whole country on dialup / ADSL, but how long it’s taking the whole country on FTTP (fibre to the premises). It’s a similar issue, as it’s not just a software upgrade, it’s a hardware upgrade as well.

How often were people upgrading computers in the 1990s and 2000s? How often are people upgrading now?

For a lot of folks when they get to good enough they stop. Understandable.

But the "good enough" of IPv4 has taken a lot of effort in the last few years. How much gnashing of teeth has NAT caused and having to invent TURN and STUN and a bunch of others things?

Anyone remember Skype supernodes?

With IPv6 you "just" have to do firewall hole punching without all the drama of packet tuple munging.

And good luck with double-(CG-)NAT hole punching.

What does one have to do with the other?

I believe that ARPANET was 100% TCP/IP at most a year after it was rolled out in 1983. Its predecessor NCP only supported 256 nodes. So, yes, things take time but likely for different reasons.