It is a way to bankrupt competing Airbnb properties. Book them all up with hundreds of fake accounts with stolen credit cards.

Nobody ends up staying in them, but it can bankrupt the Airbnb host pretty quickly if they have many properties on highly leveraged mortgages.

And why would they care if it did, if the robots are "buying" the properties, implying payment?

That makes the impression that Airbnb is always out of service, and the other platform selling Airbnb rent is more available. It creates a competitor and worsen the service of Airbnb at the same time.

implying payment, until the last second when the robot's operators decide they can only have one unit to live in. Or any other such scams