Exploring Coroutines in PHP

All the examples I find are like the trivial ones here where it just feels like instead of jamming a bunch of code into a single messy function that yields, you'd be better off particularly from a static analysis standpoint just having ordered method calls or chained callables where each step returns the next step as a callable.

I've yet to see a use case where I can't come up with a safer way to do it without Fibers, but I would love if someone could enlighten me because I feel like I am absolutely missing something.

They were added to PHP by the maintainers of amphp (https://amphp.org), which is the best library for async PHP out there, providing a clean, object-oriented and async API for files, databases and everything that can make use of async I/O.