The short answer is: Yes, smart locks are safe.
There will never be a perfect lock that’s 100% secure against break-ins; that’s why many people invest in multiple locks for their exterior doors. Traditional locks have been trusted for centuries and don’t have the added risk of being hacked, but they are still vulnerable to being picked. Smart locks offer convenience and the bonus security of being able to monitor use.
Smart or not, the security of residential locks is rigorously tested by the Builders Hardware Manufacturers Association, with the highest possible product rating being AAA.