I think there is an important observation in it though: That dynamic, loosely-typed languages will let you create code that "works" faster, but over the long run will lead to more ecosystem bloat - because there are more unexpected edge cases that the language drops onto the programmer for deciding how to handle.
Untyped languages force developers into a tradeoff between readability and safety that exists only to a much lesser degree in typed languages. Different authors in the ecosystem will make that tradeoff in a different way.
In my experience, this only holds true for small scripts. When you're doing scientific computing or deep learning with data flowing between different libraries, the lack of type safety makes development much slower if you don't maintain strict discipline around your interfaces.
For this particular example where they have to do a runtime parse to do the string to number conversion, yes. But in general static type checks are resolved at compile time, so they incur neither runtime cost nor do they increase the size of the resulting code. This is the primary benefit of doing static type checking.
Untyped languages force developers into a tradeoff between readability and safety that exists only to a much lesser degree in typed languages. Different authors in the ecosystem will make that tradeoff in a different way.