While this is an issue, there are cooperative threading libraries (mainly Lwt and Async, though the community prefers Lwt) which can mitigate most of the reason

While this is an issue, there are cooperative threading libraries (mainly Lwt and Async, though the community prefers Lwt) which can mitigate most of the reasons you'd need multithreading. Hell, because it's only single threaded, you can mostly ignore locking.