IMO, JavaScript is fine for scripting. Same with Python, Lua, and others. Great for glue code or a small feature, when the bulk of the system is written is in a saner language with proper libraries.
Any time you drag a language out of its sweet spot is gonna be a bad time.
Javascript is out of its sweet spot quite a bit, which is how we end up with typescript.
However statically strongly typed code is out of its sweet spot where prototyping and to an extent refactoring are concerned. And mercifully we now have progressively typed languages trying to fill that space.
