They're built to kill. Crazy good reflexes and eyesight, amazing jump height, claws that grab hold of tree branches, feathers, and skin very nicely. There are a bunch of strays where I live, and they are murdering machines when they don't have a bowl of food plopped in front of them twice a day at their leisure.
The only reason why cats aren't hunting us down right now is because we're too big to be prey. I read somewhere a long time ago that domestic cats have one of the highest predation success rate in the mammalian class. Meaning once they choose to actually try to hunt something they usually get it.
Keeping your cats indoors won't solve anything. Housecats aren't destroying the bird population, feral cats are. If you want to help, volunteer with your local vet or animal control to capture, spay/neuter, then re-release stray cats.
Not true. Pet cats are about a third of the problem, according to a 2013 nature paper. Feral populations vary a lot by location - some places have almost no ferals but lots of pet cats.
"We estimate that free-ranging domestic cats kill 1.3–4.0 billion birds and 6.3–22.3 billion mammals annually. Un-owned cats, as opposed to owned pets, cause the majority of this mortality."
The article also states the following regarding more popular studies in the media involving pet cats:
"The magnitude of mortality they cause in mainland areas remains speculative, with large-scale estimates based on non-systematic analyses and little consideration of scientific data"
