Python tried to add things to the language to entice developers over. The only thing that worked was finally ending python 2 support.

They tried to do the same thing with IPv6, and nobody wanted to move over to it until the warning "We're running out of IPv4 addresses".

Users actually wanted to use IPv6, organizations were somewhat neutral. The ones that were standing in a way of adoption are ISPs.

Also IPv6 was almost entirely unavailable until a few years ago. There's no point in learning how to use ipv6 if your ISP does not support it.

HE.net and SixXS have been providing IPv6 tunnels for at least a decade.

SixXS no longer does and I never was able to use them. For some reason one person assumed that information I provided were fake and I never was able to get an account with them until they ceased their activity.

HE.net works and was relatively nice experience to learn how IPv6 work, although both SixXS and HE you still had the disadvantages of tunneling like low speeds, outages etc.

It's nice to test if your application can work on IPv6, but you still won't get benefits of natively using it.

I’ve been using HE.net for years and I get full speed, equivalent of my IPv4 bandwidth. You may want to look at it again.

I guess it is just my bias against tunnels. BTW: what is your bandwidth?

Their tunnels work surprisingly well! It is only 100 megabits down, 20 up.

Thanks, that's quite good.

Well, change has high costs, that's why. So the benefits need to be big as well. I think the issue for Python 3 is the benefits weren't that large compared to the costs, and for IPv6 it's the same, albeit people know that the cost/benefit ratio changes over time as IPv4 gets more and more overloaded.