Prices have been coming down for years in nominal terms, let alone real terms. Cg nat does everything that’s needed, there are no significant ip6 only services, there are plenty of ip4 only services, so you have to support ip4 anyway, so why bother with ip6

My company has just turned off all ip6 connectivity for its corporate laptops because it’s considered a security risk. I disagree, but I do agree that having 4 and 6 is a higher risk than 4 alone or 6 alone, and 6 alone sadly still doesn’t work reliably.

All the “promise” of ip6, direct connections etc, were lost when stateful firewalls became required and memory became cheaper than $20 a megabyte. Some bespoke old protocols don’t like ports changing, which can be a problem, but it’s a very small number and easier to work around with modern protocols than support a dual stack environment securely for the majority of places that struggle securing a single stack.