Sometimes, I wonder if for the sake of small business and general good, if horizontal integration should be heavily regulated and restricted for publicly traded companies (not private ones). For example, Apple. Why aren't the software and hardware divisions separated, at a minimum? Furthermore, I might wonder, why couldn't iPhone, iPad, Mac, Audio Accessories etc. be separate companies? Sure, you'd lose a ton of the…
Software-hardware coevolution has large benefits to the consumer. What you are proposing is to just make the products worse and more expensive.
See, for example, Standard Oil. They massively lowered oil prices - we broke them up. See also AT&T. Once their usefulness as a monopoly ran out, we broke them up.
Plus, we can see that hardware-software coevolution has large benefits - but who is to say that having companies separate does not also have large benefits of its own? You might not have Windows shoving Microsoft Teams and Edge and Bing down your throat... or Apple pushing Apple Music to your parents. If Apple can't integrate, perhaps we'd have more open standards for interoperability.