@smirnoffs here's the short summary. Python: dependency management, version compatibility, and dynamic typing. JavaScript: often unexpected behavior (JS WATs), implicit conversions, constantly changing ecosystem, and dynamic typing.
@smirnoffs There are languages that are not as painful. In particular, TypeScript fixes lots of JavaScript problems. Java can be old school and heavy, but not as painfully unstable. C# (though I didn't use it for a long time) was pretty decent, especially after Microsoft unchained it from Windows