Careful with that word "we." I'm an engineer, but put a huge emphasis on industrial design. The form of my designs are integral to the function. They don't just hold the electro-mechanicals I'm designing (which is my specialty), they are the interface with my users.
So I fuss for days sometimes to get the right distances and sizes to fit 95% asian woman and 95% western men. Tweaking the curvature transition of complex surfaces to feel natural, give tactile feedback, and be able to be injection molded from a single pull mold (yeah, I do preliminary mold design too). While still containing and constraining internal mechanisms (which I also design). Choosing textures and colors that build on that base. And so on. Often I have people with industrial design or fine arts degrees consulting on the designs.
It's not rocket science, but you are right: it shouldn't just be slapped together at the last minute.
Bevels and rounded corners? Easy stuff. There's an optimum, but not a huge sensitivity. Where Apple and others excel is under the skin, as well as fit and finish.