To be clear, by “worst-case guarantee” I mean “the expected utility is guaranteed to be pretty good regardless of uy”, which is unattainable without shared randomness (claim 1).
I think you are either misunderstanding or disagreeing with a lot of the terminology on randomized algorithms and worst-case guarantees that are commonly used in CS and statistics. This article is a decent introduction to this topic.
To be clear, by “worst-case guarantee” I mean “the expected utility is guaranteed to be pretty good regardless of uy”, which is unattainable without shared randomness (claim 1).
I think you are either misunderstanding or disagreeing with a lot of the terminology on randomized algorithms and worst-case guarantees that are commonly used in CS and statistics. This article is a decent introduction to this topic.