Basically there are 3 methods for creating 3D content:
* Voxels (points in space)
* Polygon (vertices, edges and faces)
* Mathematically calculated (NURBS, CAD)
Blender uses all three but focusses on polygon modeling (triangles).The real pro of NURBS mondeling is that you are working with surfaces that can easily be shaped. That's why this method is used a lot in product development. Since all surfaces are calculated they also are infinite smooth. When you want a smooth surface with polygon modeling you need a lot of triangles.
For each category there are different tools, Blender is just one of them.
Some examples of software products per category:
product design: Rhino
car design: Alias
house design: Revit
technical components: Fusion 360
game assets: Blender
sculpting: Z-Brush
movie GFX: HoudinyI have played before with Moi3D[^1], which is "3D modeling for designers and artists", and I also use Blender and ZBrush quite a bit. My impression so far is that CAD-like specialized software is not worth using for artistic 3D modelling, at least the type which is only intended to be shown on a screen. That's because Blender's NURBS, curves and surfaces are good enough for simple shapes. For relatively complex shapes, the solvers in CAD engines can be very slow and glitchy[^2].
With a little bit of patience, one can do amazing non-destructive hard surfaces using curves and Blender's Geometry nodes (specially now that there is support for curves). With an entirely different workflow, ZBrush is a mighty hard-surface modeller as well[^3].
That's not to say that there aren't scenarios where one may have use for a solver, but they are so specialized that most artists would be better off doing the math outside their 3D modeller (or renting Fusion360 for a month, but for a casual user that software has to be more intimidating than using Python and Kiwisolver).
[^1]: http://moi3d.com
[^2]: http://moi3d.com/forum/index.php?webtag=MOI&msg=10620.1
[^3]: http://docs.pixologic.com/user-guide/3d-modeling/hard-surfac...
A 3D editor mainly intended for visual pipeline such as Blender, and a modeling application intended for producing physical shapes have entirely different constraints and intents. They both operate on 3D data, but it's best to leave it at that.
If we use text files as an analogue, then the "3D" feature in these applications is roughly a similar unifying feature as "text based input" in programming languages - or in all programs for that matter.
For text files, you want it to have specific encoding - e.g. UTF-8. For 3D shapes, you want the data to similarly follow a mathematical schema with specific topological constraints.
If you break the convention of the encoding, or the schema, you produce gibberish.
With a specific standard in place some parts of input data may or may not be transferrable between domains (e.g. CSV data is kind of lingua franca) and lots of interesting things can be built on top of that.
But generally you could ask "how is this different from" X where X can be for example Excel or Photoshop - the answer is very complex.
I can't think of any other open source software, other than Linux, that represents such a threat and valid alternative to commercial products. Autodesk be damned, even merging with Adobe wouldn't solve the Blender problem.
NURBS support in Blender is very minimal and nowhere near what real NURBS modeling packages can do.
For example, Blender can't even import STEP or IGES natively while even FreeCAD can.
https://blenderartists.org/t/nurbs-surface-creation-2-49/489... (2010)
(it may be even older than that, but I don't know about the pre-2.49 era)