> Why isn't "the operator of the scheme" synonymous with "the central actor?"
There can be multiple operators.
I see zero good reasons why decentralized schemes can't be ponzi schemes.
Your argument is akin to claiming that a three legged dog is not a dog because dogs have four legs.
I wouldn't be so uncharitable as to presume to know why you have chosen to make this argument.
I think your argument would be clearer if you took a step back and explained why you think that "central actor" is such a critical part of the meaning of "ponzi scheme" rather than a incidental feature common to ponzi schemes.