Bjarke Ingels Group (BIG) from whom these images were taken, has used SketchUp, Revit, Rhino and ArchiCAD - most recently they bought a lot of seats of ArchiCAD.
They will have produced the 3D massing models in one of these tools, and then placed the rendered output into any vector illustration program of choice - could be Adobe Illustrator, could be Affinity Designer, could be InkScape and done the outer spatial boundary heavier line as a vector drawn line there. Similarly, the colour elements, arrows and other diagrammatic elements were probably added then, in the vector program.
If these came from ArchiCAD originally, then they could have saved the views as pure vector PDFs first, then rendered a white model look for the shadows, and this would mean that when the PDF was brought into Illustrator or Designer, they wouldn't be ANY re-drawing - the lines along the spatial boundary would be selected and a heavier lineweight chosen. It's a super-simple, effective workflow, and gives incredibly clear diagrammatic output.
This kind of work is exactly the sort of thing I've been doing myself over the last decade.