For the most part, adding complexity to anything increases the chance of failure. For average people (who don't generally give out their keys) it's not a great

For the most part, adding complexity to anything increases the chance of failure. For average people (who don't generally give out their keys) it's not a great idea, but for airbnb hosts, making a key that is hard to copy is a good idea. However, I've seen some airbnbs that have a pin door code or a key fob, which are arguably more secure than a regular key lock but have less chance of failure in my experience.