Thank you for this knowledgeable answer comrade. I am by no means professional machine engineer, as you are, but sometimes I need to look at complicated pipework assembly, covered by few layers of sheets and tanks, in the STP format. This is very easy in Inventor, I suppose that with Catia it is very easy too, but I am unable to do it with FreeCAD. Maybe I am not skilled enough. Certainly, as you write, FreeCAD is not so well in assemblies. But quality of software is composed also from ease of use.

IMO, the problem isn’t that free software is incapable. The problem is if you are running an engineering / manufacturing firm you need to use software which is fully compatible with what your clients use.

I certainly agree. When the client or enterprise you cooperate with uses DWG format (as is the case most of times), you cannot use, etc., librecad.

There are many other cases, for example Matlab, editors for programmable logic controllers, software for industrial robots, etc.

Therefore, in such cases, I think the pragmatic solution under capitalism is to pirate such software. In the end, this is a mean of production and we just need to seize it. But under communism, such software could be made by state owned enterprises and the code could be available at least within all communist states.