I took the article to be saying that mpmc queues are not queues so we can use bags instead because bags are faster. The second claim seems dubious to me though. I checked out the repo which led me to https://alexsaveau.dev/blog/opinions/performance/lockness/at... which proposes new CPU instructions to create atomic bitmasks. As the author notes, the bag structure breaks down a bit because you have to operate on the bit mask with atomic operations which will contend heavily with each other.