Amazon isn't a public utility like Facebook and Twitter, its a horizontally integrated conglomerate. Amazon Cloud Services, Amazon Retail, and Amazon Digital Media needs to be split into 3 independent companies that compete with each other and can't be used to leverage advantages over firms competing in other areas. Netflix is hosted on Amazon hardware. Amazon also provides similar services. Because Amazon allows this to happen and netflix has been successful does not mean they are not more subtly violating anti-trust laws. If netflix wanted to start producing conservative programming, could bezos lean on them to stop it? I don't know that he would, but the possibility existing disincentives Netflix from even considering upsetting their cloud overlords.
We need to take a hard look at how anti-trust laws SHOULD work. Just because we have anti-trust laws on the books that Amazon(and Facebook, twitter, etc) is in compliance with, does not mean they are producing effective policy. We need congress to actually do their job and set the framework for the FTC to do their job.
They have very little willpower to upset the status quo. Breaking up Amazon is not the same thing as killing Amazon. The successor firms would be offering the exact same services as they are today. Amazon would lose some of its scale advantages creating upward pricing pressure, but it would also face new competitive pressure pushing prices down. Amazon and its shareholders would lose, but the american people would be rescued from the inevitable march towards Amazon Hegemony.