You're completely missing the point here. If you are transpiling something, you don't need to worry about syntactic sugar in the base language you are transpiling to, only what you're transpiling from.
JS is a fantastic fp language and pipe/compose is commonplace for people writing in that style already. This just adds first class support to the language
For all intents and purposes, JavaScript with all the extra features it has accreted over the years is a different language from the JavaScript of a decade ago, and a compilation step is necessary in order for web browsers to parse it.
If you're running a compilation step anyway, you may as well write the code in a language that isn't such a dumpster fire.
> JS is a fantastic fp language
Actually, it's pretty terrible at that.
If it was a different language you could say it "just" adds something, but javascript is not compiled and any syntax change means you start over as far as compatibility goes. It is unique in its scope and usage and this feature doesn't enable anything new for users and is only marginally useful for programmers.
So what’s your point, other than communicating how upset you are over a programming language? That we should be writing websites like it’s 1999?