I don't see why that is relevant. The point was that if companies have a monopoly in a product category, improving the product doesn't make the company more successful. Since macOS and iOS do not have a worldwide monopoly, Apple (and thus Tim Cook) have to improve the product for the customer to gain more marketshare.

I think Apple's problem was that one designer that was a fan of excessive minimalism wasn't matched enough by a counterforce. Now that Ive is gone, Apple takes a more functional approach to product design. E.g. the MacBook Pro has useful ports again.