Javascript is this generation's C++. It's a massive language and the only way to stay sane on a project is to agree to use a well demarcated subset of it. Nothing wrong with being C++. The reason JS is so massive and weird is because it's the language that everybody uses, or has to use at some point. Upsides and downsides.
JS as a language isn't nearly as big as C++ or, say, Swift... I'd say Python complexity is on par or even higher than JS, in terms of core language features.
There are some language features that are outdated but it's hardly like the C++ situation.