If we look at the one criterion that matters (is it, or can it be, captured and controlled) consider:
There is an “Ethereum foundation,” which raised the initial funding to create Ethereum, and to this day, coordinates changes to the Ethereum code base
The Ethereum foundation consists of persons who could be overtly or covertly pressured by governments
Ethereum promised “code is law” and then, when someone ran code that exploited a flaw in a major smart contract, the Ethereum Foundation asked major exchanges to stop trading Ethereum so they could roll the blockchain state back
50% of all Ethereum were created at launch, either for early investors or for the Ethereum foundation itself.
The consensus mechanism that Ethereum switched to, ‘proof of stake’ simultaneously rewards large holders of Ethereum and allows them to decide which transactions are and are not valid. Nothing would ever force these people to give up control over Ethereum.
What about Ethereum? How is Ethereum a Scam?