So then what would you say to the locations where domestic duck/ hybrid breed populations have lived in the wild for years? That's make believe land?
Climate/ surroundings matter quite a bit. I grew up on the Jersey shore where there's quite a large population of hybrid ducks, didn't realize what they were until recently, as a kid I just knew some of them had different colors and would never fly, but they didn't need to, so yeah they were happy. Even domestic ducks are great swimmers/ divers.
There's also a large population of hybrids down in Austin, TX on the Colorado River/ Ladybird Lake.
Maybe hybrid/ domestic flocks wouldn't be happy in your location, that's fine. They probably wouldn't be very happy in mine in upstate NY now either. That doesn't mean they can't be happy anywhere.