What are the non-network team business benefits to IPv6 over v4? That is what drives adoption.
What are the non-network team business benefits to IPv6 over v4? That is what drives adoption.
These problems will only get worse from here on out, but they're not as visible to people outside networking because this degradation of quality of service is a slow creep. The IPv4 Internet just gradually gets more and more limited in capability and less reliable for anything beyond the most basic use cases.
IPv4's address space is simply too small. There are already almost twice as many people on Earth as there are possible IPv4 addresses, and that assumes perfectly efficient utilization of IP addresses which is pretty much impossible. In reality there are probably 8-10X as many humans as viable IPv4 addresses. If every human being tends to have a computer and a phone that means there's at least 20X more devices than IPs.
You know, that used to be only "if every human being tends to have a computer", since phones didn't have an IP address. Now it's "a computer and a phone". A few years down the line, you'll have "a computer and a phone and a watch", then "a computer and a phone and a watch and a standalone VR headset", and so on.
However, assuming that I and my organization have enough IPv4 addresses (without requiring any of the tricks of multiple layers of NAT), is there a sufficient reason for us to justify the effort/expense of changing what works?
For example, I'm in the US, and my mobile device has an IPv4 IP sitting behind the mobile provider's CG-NAT. My mobile device also gets IPv6.
Since you only provide your site over IPv4, that means my opinion of your site is governed in part by my ISP's CG-NAT, which you do not control. If the CG-NAT is overloaded, or otherwise having issues, that will manifest to me as problems with your site. I will assume the problem is with your site, and take my business elsewhere. In this example, if your site was also provided over IPv6, then my phone would have skipped the IPv4-only CG-NAT, and things would be fine.
Perhaps you will diagnose the issue as caused both by the combination of your ISP flaws and my choice to be IPv4, however, the vast majority of users definitely won't, they will notice that most of the web (i.e. IPv4 web) sucks for them but doesn't suck for other ISPs and will put on the pressure on your ISP to get their stuff working to properly support the IPv4 net (or take their business to another ISP) instead of putting the pressure on IPv4 sites to switch to IPv6 or taking their business to another site.
IPv4-only still has enough critical mass (and will have for quite a few years still) to ensure that 100% of ISPs in the world have to support decent service for IPv4 only servers; IPv6-only does not yet have enough critical mass to ensure that all or even half of servers have to support decent service for IPv6-only clients - this is a quite literal chicken-and-egg problem for the motivation to switch.
Regardless, Google's chart of IPv6 adoption (https://www.google.com/intl/en/ipv6/statistics.html#tab=ipv6...) continues to trend towards IPv6 adoption. I expect that if you looked at a chart of web site IPv6 adoption, it would also be trending upwards (though not at as steep a rate).
If that's true, then it stops being a chicken-and-egg problem, and turns in to a game of chicken: Who starts supporting IPv6 first, you or your competitors?
No, unless you're running servers for users who might have those issues on their side (e.g. anyone accessing your servers from mobile). May as well wait until you can save money by giving up your IPv4 addresses.
And if you're already moving away from perimeter defense, to more identity based zero-trust, the move to IPv6 makes much sense.
But upgrading a working network is lots of trouble. Most existing businesses have plenty of public IPv4 addresses and don't have to conserve.