Through the process of using dominant market power, to anti-competitively harm competitors in various industries.
The most common one, that is in the news, is the App Store situation, where literal laws are being passed to ban Apple's behavior.
But it also applies to other parts of their business, such as ads. There could be a push to pass laws to make Apple's behavior illegal in those spaces as well.
Are you aware of the vendor lock-in concept? Combine that with a duopoly and you get your answer about milking and Apple holding a gun to consumers heads.
It's almost a "natural" path for monopolistic companies. Once it got enough market share it starts milking it. Android(google play services) and IOS lock-in is the gun you keep asking for. The whole article is about Apple switching from major hardware upgrades/innovation to charging existing customers more for services.
One simple case is storage. Would would Apple provide you greater storage capacity when they can milk you more using a "cloud" subscription.