It's interesting when you look at it from this perspective. AWS and other big IPv4 owners have a financial incentive to hold back IPv6 deployment in a convenient and scalable fashion, because that would quickly wipe out billions in value of a scarce resource. It's like some people who own NFA firearms: they support keeping the regulations because a lightning link isn't worth $15k without it, it's just a cheap piece of stamped sheet metal.
Edit: it's also an easy way to outcompete others; IPv4 space has become a huge capex for starting a cloud provider.