I would tend to agree with your open assertion that Concurrency != Parallelism. However, I'm not sure that it is really germane in this situation. I am aware that library in question here uses C++ coroutines for 'task encapsulation' according to the developer; however, this library is being compared directly to TBB and OpenMP which are two of the 'go-to' implementations for parallel computation. So I don't think the focus on parallelism in this comment chain is in any way inaccurate or misapplied.