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...
Open sourcing your product is a risky investment, and as with all risky investments, it might pay out, or it might not.
Still, there is an antitrust question (that is slightly orthogonal): if TooBigTech can offer a similar product at a loss (e.g. for free) until they capture the market, then that's a problem. And they can only do it because they are too big, and that is an antitrust issue IMO.
They can only copy what they're explicitly legally allowed to.
Elastic explicitly allowed AWS to copy and use their source code, then whined about it.
As in, they can build an alternative to an open source project, offer it for free (i.e. at a loss) for years until they capture the market, and then start enshittifying. This is an antitrust problem.
> Elastic explicitly allowed AWS to copy and use their source code, then whined about it.
Yeah at the very least they should have started with a copyleft licence.