These feel a bit piecemeal compared to a “complete” CAD tool. But it also seems like a promising start. Is there any concerted effort to build a fully featured open source tool for CAD or other physical modeling? I see some listed at https://alternativeto.net/software/solidworks/?license=opens... but am not sure how they compare to commercial products.

Freecad and openscad are basically your only choices for FOSS CAD work Freecad has pretty bad UX compared to Onshape and Fusion 360 (have to keep switching between lots of modes rather than a single unified UI), while openscad is more of a CAD DSL (that IIRC doesn't actually model solids as solids).

I use CadQuery(1). It uses OpenCascade and BREP under the hood. So far, its been pretty decent to work with.

edit: I also use Fusion360 for non-scripted stuff. The parametric modeling is nice!

1: https://github.com/CadQuery/cadquery