That particular benefit has no value if you still need to support v4.

It's almost a self-inflicted tragedy of the commons or reverse network-effect.

Adopting IPv6 doesn't alleviate the pain of IPv4 exhaustion if you still need to support dual-stack.

It still helps. I have a 1U in a colo which gives me a /64 for ipv6 and ~5 addresses for ipv4. I just set up a dual stack kubernetes cluster on 6 virtual machines. When I want to ssh into one of the machines, my options are either:

  1. Use IPv6 which works and goes directly to the virtual machine because each virtual machine grabs its own address from one of my 18446744073709551616 addresses.
  2. Use IPv4 and either have to do a jumphost or do port forwarding, giving each virtual machine its own port which forwards to port 22 on the virtual machine.
  3. Use a VPN.

Also being able to generate unique ULA subnets is super nice.

If you are an ISP running dual stack ipv4 with NAT plus ipv6, the more connections happen via ipv6 and the more traffic happens via ipv6, the better, because it doesn't have to go through the NAT infrastructure which is more expensive, and cost scales with traffic (each packet needs its header to be modified) and number of parallel open connections (each public v4 address gives you only 65k port numbers, plus this mapping needs to be stored in RAM and databases).