This article is making a misleading comparison. Yes, dynamically typed languages have overheads that statically typed languages don't. But the better question

This article is making a misleading comparison. Yes, dynamically typed languages have overheads that statically typed languages don't. But the better question to ask is why Python implementations are factors slower than leading javascript implementations, which have the same theoretical overheads that Python does. The V8 is is now about a factor of 4 or 5 off of the speed of C for general purpose code, while CPython is 30x to 100x.