... by tightly integrated visual feedback that's easy to program and low complexity processing.
Ability to program easily with a GUI and visual interface that sees things from the robots' camera perspective.
Flexible use of coordinate spaces that make programming arms with 6 or more degrees of freedom super easy. Got a bot arm with 13 linkages that can reach around corners? Easy. Simple arm with only 2 degrees of freedom, with one polar and one cartesian? Any arm geometry works.