This option would certainly improve the customer experience, and, according to Google, this option also increases booking conversion rates.

With the Book on Google model, Google in effect becomes more of the intermediary to facilitate bookings, rather than just a gatepost to provide information. It certainly isn’t an OTA either as it doesn’t become the merchant of record. But, friction through the booking process would be avoided, as would possible customer leaks towards a different property or booking platform.