In the most ridiculous scenario you try to process two high-throughput async data streams concurrently and you end up with this nightmarish "bouncing" where eac

In the most ridiculous scenario you try to process two high-throughput async data streams concurrently and you end up with this nightmarish "bouncing" where each "thread" of processing can only process until it sees an await keyword before being forced to cede control back the other thread. At this point it would be reasonable to expect that the amount of overhead would exceed the amount of real work being done, and in such a way that the text of the EcmaScript spec makes impossible to optimize or fix.