A CM is a Contract Manufacturer. Many times they also offer value-add capability like PCB layout, component selection, subsystem design, etc.
Jonathon Ivey and team handle mainly industrial design - the look and feel of the product. Actual PCB layout, mechanical engineering to make those industrial designs a reality? Much is done at the CM.
It’s not so much the research that’s leveraged, but the design. Likewise with HP, Dell, and other brands. About the only ones who really DO everything themselves are Asus, Acer, and Toshiba; everyone else pretty much uses CMs to build and do a good amount of the design of the product, especially the inside guts.
Now, Apple - like many companies - has final approval of the design that the CM does, but I can guarantee you that if the CM recommends a flex trace run a certain way, or a screw be added in a specific location that Apple - like all other PC brands - would do exactly what the CM recommends. The CM is the expert in actual manufacturing.
And that’s the dirty little secret - Apple, HP, Dell are not manufacturers. They’re concept development and marketing brand companies. They really don’t build anything - they outsource the manufacturing.
It would be like you coming up with a great idea for a new sports car, putting all your thoughts down on paper, then going to Ford to actually do the design of where and how the strut towers actually mount to the chassis, optimize the engine mounts and exhaust routing, heat shield placement, and production. You conceived the product, and you marketed it - but did you actually do the nuts-and-bolts of design (programming the CNC welders, the sheet metal stamps, choose the glues for securing parts) and manufacturing? Nope.
You have a more sophisticated knowledge of the situation but I have been saying exactly that about Apple and posting it to the Apple fan boys here. What you have laid out is what I strongly suspected. The fan boys exaggerate how much Apple does in house. I told them the Taiwanese are the geniuses of the laptop, the cell phone and the motherboard. And that Apple had some serious Taiwanese partners who are are doing the bulk of the R&D and do 100% the manufacturing in their mianland Chinese factories
What does Apple in Cupertino do? They come up with concepts, marketing and distribution. They maintain the mystique that gets people to fork out gobs of cash for overpriced products. Cupertino is the hype machine. Sure there is some R&D and engineering in Cupertino but most goes on in Taiwan by the CM partners