> everyone knows

Not everybody knows. People who learn JavaScript don't know. In fact, they must learn this. And from my experience, most learning resources don't mention this, let alone teach this. It took me a really long time to understand what ECMAScript is and how it relates to JavaScript. And the effort I put in this understanding... I would have preferred to not having needed that.

So no, not everybody knows this.

It’s possible that it also really doesn’t matter that much to the majority of people