Yeah if you want to be reductive about it, FreeCAD is a GUI wrapper for OpenCASCADE, its CAD engine. FreeCAD is designed to be extensible; the workbench system allows for several different workflows, and using the Python API it’s not that far out there to make your own workbench for specialized tasks. You could build a clockwork workbench if you were interested in designing escapements and such.
The tradeoff is it can seem overhwelming because there’s a LOT of functionality in there. I do almost all of my work in the Spreadsheet, Sketcher and Part Design workbench, plus the A2Plus assembly workbench from the addon manager.