The cost of repossessing a car isn’t zero, and even finding the car can be hard. What if the car is trashed when you repossess it? Say they wrecked it and don’t have insurance? This isn’t an uncommon scenario.
That's a pretty serious offense and it's extremely uncommon over here.
Sure, repossession can be costly but debt collection agencies will make your life hell very quickly, it's not something you can drag for years without big consequences.