Outdoor cats are illegal in the area I live... this was not a thing we realized was a thing since all neighbourhoods we lived in before it was both perfectly fine and normal.
Every time one of our cats got out we would get a 500$ fine. We had a neighbour that really fucking hated us, so one of the many things he would complain to the city for or get us fined for was if they spotted our cats out of the house, and honestly, we got warnings and fines so friggen often it was pretty clear that he was practically stalking our house to see if they got out.
One of our outdoor cats ended up getting poisoned and dying. The other one was just didn't come back one day. Another neighbour asked us what happened to our cats and was pretty disappointed to learn that they had passed. Apparently they kept the mice out of her shed (we're right across the street from a small forest area, so there are LOTS of small animals that live there, it's why the cats liked going out so much) and since they disappeared her shed and a lot of the garages in the neighbourhood have been infested with them. You honestly can't go on a walk without seeing mice run across the sidewalk or around you. (remember it's a no outdoor cats policy neighbourhood, so we were likely not the only ones that got fines if our cats got out)
Personally, I think outdoor cats are less unsightly then seeing mice everywhere and in everything but I guess that's just my opinion.