It does. It's called NAT64, and it works/breaks as well as regular NAT44.
A good majority chunk of cell carriers today have gone IPv6-only for phones. They rely on NAT64 gateways (rather than CGNAT) to access IPv4-only resources. A lot of consumer internet is slowly following that lead as a better alternative to CGNAT. At least if your customers are consumers we are really close to "You might only need to serve IPv6."
(It's the "Enterprise-grade internet" that is interestingly lagging and falling behind in IPv6 adoption, and maybe doesn't see enough reason to support IPv6-only well; especially if the cost of IPv4 plateaus again, as some suggest it might. Recent AWS cost increases for IPv4 have been something of a call to action to some Corporations, but in general if you are B2B you probably need IPv4 support for a while longer as the economic incentives games play out on a long, slow horizon.)
If ipv6 had been designed form the start to allow seemless transparent access to ipv4 from an ipv6 only client that would be fine. But dual stack means twice the work and very little benefit (what services are ipv6 only, even today)