The problem with Javascript IMHO is that it's difficult to say "enough". As someone who uses it everyday and loves it, I believe it's in a decent place now, but it keeps adding more and more strange operators that virtually no one uses or has use for in everyday applications. Things like Symbols, BigInt, etc. are way too rare in JS and only useful under certain "ideas of workflows" to be worth being part of the core since they introduce a whole incompatible layer of dealing with things and don't mix well with the rest of the language. I'll even throw "classes" and "generators" to the list of things that were a mistake, as time has shown.

This is the same with the pipe operator, we already have arrow functions, thenables, and TWO different types of .pipe(), which makes syntax a lot cleaner when needed. IMHO adding this pipe operator "|>" would be a mistake, it only complicates the language making:

- Browser competition harder, when the language is really broad and difficult it makes it harder to create a new engine.

- Mastering Javascript harder, there's a lot broader amount of concepts there which are not really useful except.

- No real benefit as I explained. For some people's worldview it's better, but for us the rest of mortals[1] it's just overhead.

A really good indicator of whether something is useful in core JS is: has someone made it into a library or sublanguage[2] that is widely used? Or a language feature? Promises and events def passes that test, while Symbols, classes, generators and this new pipe operator definitely don't. Bigint is arguable, since it passes the test but remains fairly fringe use-case in JS.

[1] Note that I'm the first one to experiment with JS and try weird things! I'm just saying that these should remain broken experiments on my computer, or nice libraries in npm, but not part of the specification that no one uses.

[2] Coffescript, JSX, Typescript, etc.