I would argue that a lot of Blender’s complexity comes from it being a parametric modeling system.

Take Blender, a parametric modeler, for example. The downside to parametric modeling is that it is generally more complex. Parametric systems are usually history based, meaning you can go back into your model and adjust something (say the width of a line) and the software will automatically adjust everything that is related to it by constraints that you define. You can define constraints, relations and dependencies to objects so that if you change something it will relatively impact other things. Parametric modeling means that your design maintains the original geometry of each object even after you apply rounding and smoothing.

It is useful for quick prototyping, but likely won’t be used for the final product. Basically direct modeling means that you work directly with the geometry you see and each edit direct impacts the underlying objects.

DesignSpark Mechanical is a direct modeling tool as opposed to a parametric one.

Designspark mechanical 4.0