The robustness and flexibility of a constraint solver (including limited symbolic capability) is what I enjoy the most when using systems like Inventor and Soli

The robustness and flexibility of a constraint solver (including limited symbolic capability) is what I enjoy the most when using systems like Inventor and SolidWorks, compared to say OpenSCAD. Compared to hard-coding dimensions, proper usage of constraints encode semantics and design intent (e.g. mating, clearance, symmetry) into the 3D model and makes it a lot easier to reason with.