CPE support for IPv6 has generally been garbage with it taking 15-20 years before the bare minimum was supported by mainstream router vendors. Even today there are still vendors that assume only IPv4 support. In my opinion the IETF really screwed up when they made IPv6 more complicated than just IPv4 with more address bits. The incumbent in my area generally uses PPPoE in their access network, but routers that supported PPPoE and prefix delegation basically didn't exist in 2010, and only started being available circa 2015 (in part due to the required bits not existing in OpenWRT and the hardware vendors' software development kits for their chipsets). Sure, we're 10 years further on now, but there remain a number of vendors that only support IPv4 for management of devices (cough Ubiquiti cough) in parts of their product line.
That said, there are features of IPv6 that are absolutely awesome for carriers. The next header feature that pretty much eliminates the need for MPLS in an IPv6 transport network is one such item that makes building transport networks so much cleaner when using IPv6 than IPv4. No more header insertion or rewriting, just update one field and fix up the delta on the checksum and CRC. They just aren't really applicable for smaller networks.
I do think NAT64/464XLAT is a pretty good architecture for new ISPs that can't get their hands on IPv4 space, though. Or even MAP-T, but CPE support isn't really there yet.
How many ask for IPv4? I understand your situation, it's a lot of work, for something that many won't notice. It's just that saying there's no demand because your average consumer, who also doesn't know what IPv4 is, isn't asking for it, is the mentality that keeps IPv6 from being implemented.
On the funnier side of things, we've also sometimes run into the opposite problem that we can't reproduce an issue, because it's only on IPv4 and 95% of the time everything we do is IPv6. But we're also not serving home users.
Now apply that to IPv6 and you can see the point that (I think) GP is making.
Side note: The claim it is not widely used doesn't track. How many people use Google or Facebook? More than half of that traffic is over IPv6.
https://circleid.com/posts/ipv6-usage-in-the-u.s-surpasses-5...
It's not widely used in my customer base as well as among a number of other small independent ISPs I know of. A significant number of the CPE we have deployed today do not support IPv6, therefore a significant number of our end users will not be using IPv6 resulting in only partial usage. That is what I am referring to: an incomplete deployment of IPv6 across a customer base without their knowledge of change and the end user's ability to identify issues will cause support issues which costs money and time.
Because of how IPv6 is provisioned, going from a no IPv6-deployed state to fully-deployed state will encounter transition issues. It's not provisioned the same way as IPv4, and that's the whole bloody problem!!! Sure, I can turn on handing out IPv6 addresses from our edge routers via PPPoE today, but it's not going to "Just Work" for all customers without CPE config changes (assuming the CPE even supports IPv6 in the first place for which a bunch of them do not!). It's a complete pain that has less than zero benefit for a small provider today since everything is available over IPv4 and nothing is IPv6 only. Heck, another ISP I know had a customer ask for IPv6 support, and then the customer didn't even bother to provision it on their own router!
Another example: take Ubiquiti's AirCube product line. It doesn't support IPv6. To deploy IPv6 it would be necessary to reconfigure things to make the ONU for the customer act as the router for the customer's home network and place the AirCube in bridged mode. That's assuming that the ONU even supports IPv6 yet as it did not when I looked into it on the order of 6 years ago. And yes, there are a few dozen customers on AirCubes that fall under this case. This means moving into a territory where multiple different CPE deployment configs are now required for less than zero benefit.
That there are gaps in IPv6 support has been a problem, is a problem, and will continue to be a problem. The industry isn't 100% IPv6, and I don't see how that is going to be the case in the next 5 years or even the next 10 years. Consumer gear isn't there yet. That was the problem 5 years ago, that was the problem 10 years ago, that was the problem 15 years, and that was the problem 20 years ago... What's different today that's any different than yesterday?
It's easy to deploy IPv6 in data centers where you control all the infrastructure on servers where operating system IPv6 support was mature decades ago. It's not so easy as a small ISP when dealing with pile of random consumer gear that an ISP's customers bring to the table where IPv6 support remains hit and miss.
And then you say `Nobody asks for IPv4` - so nobody asks for IPv4 and 0.5% ask for IPv6?
So, yeah, I don't see IPv6 being relevant as a small ISP today.
Big, evil, hated Comcast has full ipv6, and I doubt any of its customers asked for it either. Instead people complain they’re only getting a /60.
Some people will say monitoring is all that you need, but I do not agree. There are a million different little issues that can and do occur on physical networks in the real world, and there's no way monitoring will have a 99% chance of detecting all of them. When incidents like the partial Microsoft network outage that hit certain peering points occurred, I had to route around the damage by tweaking route filtering on the core routers to prefer a transit connection that worked over the lower cost peering point. It's that kind of oddball issue that active users catch and report which does not happen for barely used services like IPv6.