Fusion is orders of magnitudes better though.
It's used by mechanical engineers. It's what you use to design an engine. Good CAD software hooks up to the inventory system so that parts can be ordered automatically.
It's used by electrical engineers. Special CAD packages exist for integrated circuit design, magnetics, and antennas. For example a motor might contain coils of wire, permanent magnets, air, and various components through which magnetic field lines are directed. Eddy currents must be analysed.
It's used by chemical engineers. Pipes and tanks and pumps get laid out. Stuff like water hammer must be accounted for, except maybe the fluid is poisonous and explosive. Expansion joints for thermal stress and pressure changes might be important. Stress on welds must be calculated.
The age of the product would surely reveal the difficulty of creating a competing product...
In solidworks (to pick on the one I am most familiar with, NOT expert with) you can click on an edge and say "radius this". In Solidworks, you can have a master model drive dimensions down to other drawings, so that multiple people can work on different parts of the same system and get the bolt holes to line up. In Solidworks, you can say "give me 2% draft angles on these faces, and run an injection mold flow analysis."
Openscan is cool and I use it, but nobody would confuse it with Solidworks or similar.
Almost all drafters and fabricators just want to interact with the 3D model with the mouse. Dragging and adding features.
Also 2D drawings are the main output of a CAD program, to build the designs from. Which Openscad doesn't provide.