I totally see where you're coming from - in my mind I had something like a modern ARM microcontroller (STM32 and the likes) where the functionality is 99% internal to the chip. For example, adding an SD card or CANBUS interface to a project - not too much you depend on the customer for in that regard.

But then again I'm at this very moment doing a board bringup for a Tegra AGX system and I wouldn't advise anyone on doing that on a fixed price contract!