It's just not worth it. the only thing keeping it alive is people being overly zealous over it. if the cost to implement is measured as '1', the cost to administer it is like '50'.
To start with it requires support v4 as a separate network, at least for internal networks, since many devices don't support ipv6 (I have several AP's, IoT devices,etc.. bought in recent years that are like that). Then the v4->v6 nat/gateway/proxy approaches don't work well for cases where reliability and performance are critical. You mentioned NAT, but lack of NAT means you have to configure firewall rules, many get a public ip by their ISP directly to the first device that connects to the ISP modem,exposing their device directly to the internet. Others need to do expose a lan service on devices (port forwarding) which is more painful with v6. DHCP works very simply, v6 addressing can be made simply too (especially with the v4 patterned addressing - forgot its name) but you have multiple types of v6 addresses, the only way to easily access resources with v6 is to use host names. with v4 you can just type an IP easily and access a resource. Same with troubleshooting, it's more painful because it is more complex, and it requires more learning by users, and if you have dual stack, that doesn't add to the management/admin burden, it multiplies it. It's easier to tcpdump and troubleshoot arp, dhcp and routing with v4 than it is ND,RA,anycast,linklocal,etc.. with v6.
For mobile connectivity, ipv4 works smoothly as well in my experience, but I don't know about your use case to form an opinion. I don't doubt IPv6 makes some things much easier to solve than ipv4. I am also not dismissing IPv6 as a pointless protocol, it does indeed solve lots of problems, but the problem it solves is largely for network administrators, even then you won't find a private network in a cloud provider with v6, for good reason too.
there keep arising more solutions, public ip usage hasn't been increasing as it did in past decades either. most new device increase is on mobile where cgnat works ok.
that's great, but when you have a networking issue, you have to deal with two stacks for troubleshooting. it would be much less effort to use just ipv4.
You're not paying for IPv4 addresses I'm sure, so did ipv6 solve anything for you? This is why i meant by zealots keeping it alive. you use ipv6 for the principle of it, but tech is suppose to solve problems, not facilitate ideologies.
But that's slow, and it's one more thing you have to setup and that could fail. What is the benefit to me if I used ipv6 and those nat services? what if I run into a service that blocks those nat IPs because they generate lots of noise/spam since they allow anyone to proxy through their IP? Not only does it not benefit me, if this was commercial activity I was engaging in, it could lead to serious loss of money.
At the risk of more downvotes, I again ask, why? am I supposed to endure all this trouble so that IPv4 is cheaper for some corporation? even then, we've hit the plateau as far as end user adaption goes. and I'll continue to argue that using IPv6 is a serious security risk, if you just flip it on and forget about it. you have to actually learn how it works, and secure it properly. These are precious minutes of people's lives we're talking about, for the sake of some techno ideology. The billions and billions spent on ipv4 and no one in 2026 is claiming ipv4 shortage will cause outages anytime within the next decade or two.
My suggestion is to come up with a solution that doesn't require any changes to the IP stack or layer3 by end users. CGNAT is one approach, but there are spare fields in the IPv4 Header that could be used to indicate some other address extension to ipv4 (not an entire freaking replacement of the stack), or just a minor addition/octet that will solve the problem for the next century or so by adding an "area code" like value (ASN?).
Eh. IPv6 is probably cheaper to run compared to running large scale CGNAT. It's well deployed in mobile and in areas without a lot of legacy IPv4 assignments. Most of the high traffic content networks support it, so if you're an eyeball network, you can shift costs away from CGNAT to IPv6. You still have to do both though.
Is it my favorite? No. Is it well supported? Not everywhere. Is it going to win, eventually? Probably, but maybe IPv8 will happen, in which case maybe they learn and it it has a 10 years to 50% of traffic instead of 30 years to 50% of traffic.
