Isn't the wider problem that people don't try to understand the internals? Some of us may read the code of modules we "require", but experience tells me this is

Isn't the wider problem that people don't try to understand the internals? Some of us may read the code of modules we "require", but experience tells me this is a rarity. For those that do, this isn't an issue, and for those that don't, this isn't an issue either. Their mental model may be flawed, but as long as the IO is the same, do they really care? Concurrent mode isn't really a black box. Its just a shortcut to throw away work that would otherwise be invalidated.