I don’t know what you mean by ISPs in the US don’t have NATs. They most certainly do NAT at the gateway device. But they also typically provide a way to DMZ to your own router instead. I don’t have to deal with double NAT simply because I effectively have my ISP gateway in bridge mode (forwarding all traffic to a specific device, in this case, my personal router).
Note: I have gigabit FTTH from AT&T. I left cable internet the moment fiber service was made available.