There was a time when these companies essentially targeted different audiences (or markets). Perhaps they are merely converging to the same markets, which would

There was a time when these companies essentially targeted different audiences (or markets). Perhaps they are merely converging to the same markets, which would make them seem much more alike now than in the olden days. As a company becomes more diverse, there is an increasingly greater chance of overlap with any given other company. Although not a solid rule, less focus tends to result in less unique innovation since the R&D is spread too thin. There are, of course, areas where each company is still unique.