People not sterilizing their cats, regardless of indoor or outdoor (with the sole exception of breeding them) is not fucking cool. Anyone ever experiencing the bodily stress a cat goes through during pregnancy should realize that, and it is also bad for males because of increased territorial stress (they tend to try to have a larger territory, which puts them into more conflicts when outside and makes them half-insane inside)

No letting your cat roam = no problems, and the local wildlife will thank you too.

Animals procreating isn't really unnatural. There are many good reasons to get pets spayed and neutered. But not that having children is bad. And the "suffering" doesn't go away if the cat is held by some breeder.

Not to mention that not doing it increases cancer risks.

"Remember to have your pets spayed or neutered." -Bob Barker

Yep, especially with female cats.

"Fix me now" - Garbage

I lost one of my girls to breast cancer because she got spayed later in life. Get your cat spayed please, it's shitty to your cat to not do it.