Current cruise missiles are optimised for long range but not for final target accuracy, they actually use onboard offline terrain data to cruise to their target. Accuracy of 99% is considered bad as it might mean collateral damage. Also final target is predefined and aborting or changing target is non-trivial.

With these so called "suicide drones", human operators can actions based on current situation, like, pinpoint the target based on realtime images, that actually means limiting collateral damage because of machine errors. which also gives them ability to abort if situations have changed substantially.