As other comments note there are plenty of problems restricting queues to ordered execution. For most use cases that simply does not matter. What matters are re

As other comments note there are plenty of problems restricting queues to ordered execution. For most use cases that simply does not matter. What matters are related features like avoidance of starvation or execution bias. And those are perfectly possible to do with multiple consumers/producers. > Lockless queues are slow That particular implementation of a lockless queue may be slow, but that is not globally true for lockless queues. There are variants, for example BBQ, https://www.usenix.org/conference/atc22/presentation/wang-jiawei https://www.usenix.org/conference/atc22/presentation/wang-ji..., that have great performance.