What is the difference between Eplan/Elcad/Autodesk Electrical vs Altium/Eagle/KiCAD?
Altium Designer, Eagle, and KiCAD EDA are full PCB design packages. Drawing a schematic is only a portion of the workflow.


Managing component libraries and footprints;
Managing connected nets, buses, and pins;
Simulating and testing circuits;
Connecting to vendors and/or managing component selection alternatives;
(Perhaps most importantly) Full CAD support for designing multi-layer circuit boards;
Much more...


By the looks of it, from cursory searching: Autodesk Electrical; EPLAN (eView, Electric P8, Cogineer, Pro Panel, and a myriad of other offerings); and ELCAD Aucoplan are aimed more at manufacturing and automation industry professionals who need to wire and document complex equipment and/or entire buildings, PLCs, robots, industrial processes, and the like.

The three packages you list are more about documentation and wiring diagrams than about multi-layer printed circuit board design.

You might want to review this question about different types of diagrams, though it is more specific to electrical PCB and device engineering than the much broader scope of electrical data and energy in various industries.