"This Note argues that the current framework in antitrust—specifically its pegging competition to 'consumer welfare,' defined as short-term price effects—is unequipped to capture the architecture of market power in the modern economy"

It's an opinion piece stating that law ought to be changed, not that Amazon is doing anything illegal.

I never really quite understand how people think antitrust law applies to Amazon. I don't have expert-level knowledge of Amazon's various markets, but I don't think they have a monopoly in any of them.