I see where you are coming from. Preemptive multitasking definitely introduces room for errors which are not possible in pure cooperative multitasking - like Ja

I see where you are coming from. Preemptive multitasking definitely introduces room for errors which are not possible in pure cooperative multitasking - like Javascript. However with multi-threaded languages like C++, C#, Java, Rust, etc. you always have to care about all of that complexity. Including ones where you cooperative coroutine might be resumed on a different OS thread. So it keeps being harder. Also after moving to Rust, traditional threading lost a lot of its scariness. The type system is just so good at preventing the multithreading errors.