good question. The short answer for one use case is to adhere to DRY principles: e.g. wanting to reuse GenStage components that do the processing, especially when the processing needs to happen with shared rate-limiting/concurrency limits. E.g. stream X does one set of API operations, stream Y does another set of operations against the same API, and they get processed in the same GenStage consumer because all operations share the same usage limit defined by that API.
It sounds like if the execution flow is expected to be distributed across multiple nodes, then perhaps it’s better to send messages with “simple” payloads, e.g. a simple list instead of a stream.
