I'm not sure you're answering my question, though. You made a claim that state machines are easy to debug and coroutines are not. What makes you think they are

I'm not sure you're answering my question, though. You made a claim that state machines are easy to debug and coroutines are not. What makes you think they are not? I'm really just curious. FWIW I've done significanly more work with state machines in the past, and I find them reasonable to debug, though not as easy as straight line code because in the latter the full state history (execution stack) is always known, while in state machines you usually need to do extra work to trace how the machine got to some state.