Did anyone try a delta robot that was not a 3D printer?

There are loads of "professional" cool delta robots used in factories to put pancakes on top of each other that use servos, and loads of 3D printers that use sliding mechanisms to do the "delta thing". Why do they seem to be two completely different worlds? Would the servo machines be super 3D printers? Would the sliding machines be cheaper replacements for the pancake machines?

I'm thinking of making a "sliding" delta robot like Delta-Six to move around boxes like the servo delta robots do but apparently that's a bad idea?