So software like CAD is funny. Under the surface, 3d CAD like FreeCAD or Blender is taking vertices and placing them in a Cartesian space (X/Y/Z - planes). Then it is building objects in that space by calculating the mathematical relationships in serial. So each feature you add involves adding math problems to a tree. Each feature on the tree is linearly built and relies on the previously calculated math.

Editing any changes up tree is a massive issue called the topological naming problem. All CAD has this issue and all fixes are hacks and patches that are incomplete solutions, (it has to do with π and rounding floating point at every stage of the math).

Now, this is only the beginning. Assemblies are made of parts that each have their own Cartesian coordinate planes. Often, individual parts have features that are referencing other parts in a live relationship where a change in part A also changes part B.

Now imagine modeling a whole car, a game world, a movie set, or a skyscraper. The assemblies get quite large depending on what you’re working on. Just an entire 3d printer modeled in FreeCAD was more than my last computer could handle.

Most advanced CAD needs to get to the level of hardware integration where generalizations made for something like Wayland simply are not sufficient. Like your default CPU scheduler, (CFS on Linux) is setup to maximize throughput at all costs. For CAD, this is not optimal. The process niceness may be enough in most cases, but there may be times when true CPU set isolation is needed to prevent anything interrupting the math as it renders. How this is split and managed with a GPU may be important too.

I barely know enough to say this much. When I was pushing my last computer too far with FreeCAD, optimising the CPU scheduler stopped a crashing problem and extended my use slightly, but was not worth much. I really needed a better computer. However looking into the issue deeply was interesting. It revealed how CAD is a solid outlier workflow that is extremely demanding and very different from the rest of the computer where user experience is the focus.