Sure. Let them out so they can fight stray cats, get preggo, get flees and ticks, and all of that fun stuff…
Mine's spayed and wears a seresto collar (which is easily the most effective flea/tick control I've seen - they're pricey for flea collars but being good for 8 months helps mitigate that. Both dogs and the cat wear them.). Now, she does occasionally get into fights with other cats in the neighborhood but that's largely unavoidable. If it's not going well she runs inside to her dog for comfort.
She was supposed to be an inside cat, but we put in a dog door for the dogs and she figured it out from them. It's a pretty basic one without the bells and whistles and electronic lock controls and triple the price. If it were it wouldn't slow her down much, she'd just come and go under the taller dog.
They can't get pregnant if they're spayed. They can be made resistant to fleas and ticks. And how are they going to fight stray cats, when they're not in a stray cat's territory?
I have a dog door, they let themselves out when they feel like it, for the most part when and for how long they'd like (it's a fenced yard). The cat learned the dog door by watching them, she also lets herself out.