AS to the USA, Pet cats in cities and suburbs are best left indoors. IMHO, a cat outdoors in those areas is abusive to the animal. Many subdivisions and HOAs in the states ban outdoor cats, not just for the protection of wildlife, but for the protection of the cats themselves who are nothing more than coyote snacks in most areas. And if you think about it, there are about 2 coyotes per square mile in the East, they breed fast, and in many areas, they are hard to shoot or even unhuntable due to law.
In rural areas, I have no problem with barn cats, with the same caveat of coyote, bear, cougar, owl, eagle, hawk, fox, snake, bobcat, gator and wolf predation. Personally, I would not let a cat out in any area, especially in a rural area.
There is no accounting for the differences in the way folks treat animals. I beleive the ethical way to treat cats in the English speaking world is to have them spayed or neutered, not let them roam.
I also think the hunting skills of cats are way overrated, and their effect on wildlife minimal. Even feral clowders leach food off humans.