My methodology was: go to https://lemmy.world, hit "All", look at IPvFoo.

So I guess my definition of a major instance is one with enough content to reach the front page of lemmy.world.

The more servers have IPv6 support the more it will become the standard and we can finally switch to it instead of IPv4.

Now why you'd wanna switch, the main reason is there are far too few IPv4 addresses available for every device to actually have a unique IPv4 address, and that results in all sorts of headaches.

Basically, the Internet ran out of IPv4 addresses to distribute about ten years ago. People knew that would back in the 1990ies, so they invented IPv6 with the idea that the Internet would eventually switch over to an address format that had enough addresses for basically forever. Ever since about twenty years ago, network technicians have introduced an increasing amount of hacks and shitty workarounds that would undermine and erode a lot of the egalitarian ideas and principles that originally underpinned the lowest levels of the Internet stack was originally built upon.

Just try hosting a computer game on a modern internet connection. On many (not all) modern internet connections, that doesn't work anymore, because you are effectively behind double NAT, and the second layer is controlled by your ISP. There is a reason why many modern multiplayer games say "fuck it, we'll host it for you". Or even "fuck it, we'll tell the user to rent a server in a datacenter if they want to host." (Note, games are just an example. There are plenty of examples where earlier internet users had some degree of autonomy when interacting with one another where current users can only hope for the continued benevolence and cooperation of Google and the like.)

By today, even though you don't really see it as an end-user, the IPv4 internet is basically held together with spit and duck tape. And also an honest-to-goodness black market for IPv4 addresses.

However, the big and obviously advantageous switch still isn't happening. There are hardly any services out there that will work via IPv6, but not IPv4, so there is no visible incentive for end users to even want IPv6. In fact, most won't even know what that is. (Technically, there is one: A Japanese site from like 1999 that will show you an animated gif of a turtle instead of a static one if you visit via IPv6. Somehow that hasn't yet convinced grandma from down the road to switch to an ISP that promises high quality IPv6 connection...) On the flip side, anybody offering a service on the Internet knows that it absolutely must be reachable via IPv4, even if that's expensive and cumbersome, while IPv6 is kinda optional, even if those addresses are a dime a dozen... million.

The whole thing is a bit of a catch-22 at this point, and even though all the experts know, and have known for 30 years, that we must switch over eventually, no real progress seems to be made lately.

Lemmy.world getting or not getting an IPv6 address is not going to make or break this. Still, it is irksome to see it being one of those obstacles that keep standing in the way of progress.