Archicad also has been developed "for decades", sure.
The difference is that McNeel has been developing mainly the "geometry engine" while Archicad's is a BIM tool (documentation, collaboration, issue management, IFC support... In comparison, Rhino's support for all these functionalities is (almost) inexistent.
But geometry in Archicad is mainly based on primitive solids and discretized curves. And this is ok IMO. Good enough for 99% of the architectural projects. Digital Project from Ghery technologies was developed to support the geometry limitations of BIM tools like ArchiCAD.
Rhno and Archicad. Two apps, two purposes.
By the way, Archicad is already 'very' parametric software, isn't it? Certainly, not the same explicit parametric modelling paradigm as in Digital Projects, for example, but still parametric. Maybe you are looking for a different app?
When can we expect the macOS release?