> CAD is only half of the design process

I'm not a mechanical engineer but I would be surprised if it was even 30% of the process. Materials, manufacturability, durability, fitting into other requirements. Some of those things can be part of the CAD design, but there's so much more.

Not to say that CAD isn't a big chunk!

Agreed, it's probably 10% of the total product development process, but approximately half if you're just considering "design" tasks.