Well you'd have to imagine a lot more collaboration between companies, so say company A just markets CPUs in the US nothing else, while company B works on just shipping logistics (to stores which handle the actual delivery to end customers). I think the real problem is that so many boundaries between disciplines make novel collaboration strategies between the parts much harder. It's difficult for say a marketing person to suggest a change to the box design
So, Intel would be split into ~2400 50-person companies. Coordination of those, through contracts, threats and lawsuits would be nightmare. A basic economic theory ("theory of the firm") says that large companies are created, because they decrease the friction that exists when many small companies (or even just individuals) cooperate to achieve a large and complex thing.
I think I agree it would be worse, though not without advantages. It’s really hard in the normal economy to work out how much a subunit of a company is contributing to the overall success and it can be hard to contain the urge to exaggerate. I think this is why big companies grow inefficiencies and at least with many small companies the individual parts could compete and occasionally fail.
