It has nothing to do with ISP greed. There is no shortage of IPv6 addresses, and, ISPs have every motivation to encourage their customers to use their IPv6 space.

The reason NAT doesn't go away is that customers don't want to use their ISPs IPv6 space, they want their own provider independent space.

The easiest way to do that, is to address all your devices from RFC 4193 ULA space, and then, on your perimeter, do RFC 6296 Network Prefix Translation to the ISPs IPv6 space.

Then, when you change ISPs, you simply make a single change on your perimeter rather than having to renumber hundreds of internal devices, DNS, configurations, etc...