FreeCAD->OpenSCAD->Fusion->back to OpenSCAD.
Some tasks are extremely easy in OpenSCAD. Fusion is not that hard either, but it is a commercial tool with a free-ish version where they keep your designs hostage. It doesn't run on Linux which makes life hard for multi platform folks. Also, in past I have had issues with STL generated by Fusion.
OpenSCAD is not perfect though, for example is missing important functions such as alignment and assembly
As for me, [proprietary 3D CAD]-> SolveSpace, since 2013.[0]
99% of the time I don't have to deal with that, but that 1% is pretty annoying.
One thing Autodesk is truly infamous for industry-wide is being the utter worst when it comes to file formats.
They make their file format unreadable by anything other than they products by design.
And even within their own product line, it sometimes doesn't work.
So I'll ask you this: what can you do with your f3d file?
Can you import it into blender to render it with a proper rendering engine?
Can you open it with a text editor and change things in it?
Can you convert your model to a format that's readable by other tools?
Can fusion import models created by other tools?
B-rep solid export (STEP) is also very much a thing, you can exchange solid models between Fusion, SOLIDworks, FreeCAD, etc. (and import them from PCB design software and so on)
But this is just baked geometry of course. It's not parametric. There is no standard for parametric models, there is no way to exchange them between different programs.
Vector drawing software faces a similar problem. There's some agreed primitives but often you just get bezier soup.
This is apologism.
If their parametric export format was documented readable ascii text, there would be an entire ecosystem of 3rd party tool taking care of connecting it to other things.
Even better, if there was a push from them to design a standard for this, this would benefit the entire CAD/CAM/manufacturing industry.
But AutoDesk's mindset is the walled garden / captive audience business model.
The fact that creating open standards around their file format would actually benefit their business is simply something that's completely impossible to understand at the corporate culture level.
While that is true, the fact remains that there is no industry standard file format for exchanging parametric CAD models.
Everything is proprietary. I.e. if you export in something you can import elsewhere you need to 'bake' parameters into geometry.
This is not a problem Autodesk created.
And while it may be true that it is also not in their best interest to solve it this is not a good excuse to bash them over adding yet another proprietary parametric format to the list for their flavor of such modeler.