That IO is roughly the same. The point of Haskell is not to "have IO". It's to know that when something is _not_ in IO, it's pure. _That_ is what other language

That IO is roughly the same. The point of Haskell is not to "have IO". It's to know that when something is _not_ in IO, it's pure. _That_ is what other languages don't have. (Although they could, as far as I know. It's a _restriction_ on exposed primitives, not a feature.)