I'd rather my two elder cats had more time outside, but I do take them for walks. Under supervision. There are coyotes here. Wolves. Predatory birds. The great horned owl is more than big enough to take out a cat...they've taken down foxes. The cooper's hawk takes down chickens, which are bigger than my cats. We also have bald eagles which are always looking for easy meals. (Yes, we're close to a river.) Generally I let them play in the yard while I'm out there working in the garden.
As for birds, there has been major loss of bird, and animal, life in my local area logging the forests and people putting in big lawns and then using spray on them. I have birds here that ought to be in the high mountains, but those got extensively logged, so the birds are here. The hills behind me are being logged again, county owned land, only the gods know why they're logging in February, 1/4 mile back, the racket is incredible in the day time. Most of the local old growth forests have been cleared to make housing developments over the last few decades. (I've lived here 63 years, I know what it used to look like.) I'm sure people are more than happy to blame the disappearance of wild birds in those areas on domestic cats while avoiding the mirrors that'd tell them that cutting down the habitat and then planting a house and alien foliage there BY HUMAN BEINGS did more damage than any amount of pets of any species.
There are NO feral cats out here, not any more, even if we're where the clueless idiots from the city dump the pets they decided just didn't fit their decor. A very large coyote pack picks off anything it can reach. I had to rescue the deer from them the other day, the coyotes were trying to run them to death.
Why are the birds, and the animals, here, in my yard? I'll you why. Have any of you actually LOOKED at the packets of photos I posted here in the store? "Rowan's Forest" being a prime example. That's MY land. It's in Open Space, a nature conserve. Forest that's more than a hundred years old. I have the pictures up for sale to help raise money to pay the taxes due to keep this place wild.
Correction: The two packets taken ENTIRELY on my own land are "Forest Mist" and "Rowan's Forest". The rest were taken elsewhere.