It seems like you’re talking about something similar: https://true-async.github.io/en/docs/components/thread-pool....

I’ve also wanted parallelism in PHP for a long time. Especially the kind of parallelism that works together with concurrent I/O. That’s when it becomes truly useful, not just a toy.

Asynchrony will always be a complex tool because of the number of states involved. That’s true. But if it’s made convenient and used properly, it becomes enjoyable to work with.