In terms of antitrust, I believe that if you could prove that Amazon forked and offered the service with the intent to crush the competition, it would be downright illegal. A current case is Meta: back then, Zuckerberg was happily writing (internally) that Facebook needed to buy WhatsApp and Instagram and Snapchat to prevent them from ever competing. This is anti-competitive.
This post explains it well: https://pluralistic.net/2025/04/18/chatty-zucky/#is-you-taki...