Australia wants to force cats to stay inside or give them a curfew because they are murdering so many other animals they are a threat to the country's biodiversity
Partially. It also relies on the cat listening to the owner when they try to get them inside. Some cats will, but most come when they feel like it. "Like herding cats" has its meaning for a reason.
Pets in general shouldn't be allowed to roam freely outside. There's too many dangers to them and things they can do to cause problems.