[vetinari]

Not explicitly. It is used by platform libraries that these application use. Given that they are provided by the platform vendor - the same that pushes DX - it's no wonder, that it was being pushed there.

CAD, GIS, or other applications that need to use 3D explicitly, on the other hand.... Basically only Autodesk ventured there, with 3ds Max and AutoCAD (since 2015).

[pjmlp]

Well, Autodesk products are market leaders, probably Catia is the only alternative.

[vetinari]

There are actually many CAD packages, with different levels of complexity, from Siemens NX to VariCAD, plus myriads of domain-specific ones, like ArchiCAD.

For example, most of our customers prefer MicroStation, for some reason (no, we are not Bentley shop ;).