An interesting use case of OpenSCAD is open source hardware with many contributors - the reasoning being that we only have mature version control tooling for text-based files (say git), and so your CAD design should be text-based. I was introduced to this idea by https://openflexure.org/projects/microscope/ - they managed to build a fairly complex 3D printed microscope project on this principle.

I'm aware of Onshape having a git-like workflow as well, wonder how the two compare! A fully cloud-based suite would probably not work well for an open source project.