Not every cat that goes outside is killed or becomes invasive. Alot of responsible cat owners let their cats out and let them roam. If you truly know your cat then you should know whether your cat truely enjoys being outside and is smart enough that he or she would survive being outside. My uncle has had his cat live outside for around 10 years. Still lives at home and has a custom built post/hideaway that has runways etc. and is huge. Still is docile, good with children and comes and goes as he pleases. Our cat is the same. He has been infatuated with the outdoors since he was young and prefers to be there just as much as he does inside if not more. He is neutered and has his shots as well, he has brought home rodents and makes it a point to show us his gifts lol. I know there are a lot of irresponsible cat owners who abandon their cats but there are just as many that KNOW their animals and give them what they really want to let them be happy. Not saying that every cat wants that life but some do. Speaking of which here he is in all his beastly glory 🤗😍