You're missing the point here, which is not that each of these languages has something JS does, it's that Perl, Python, Ruby etc all support all the same featur

You're missing the point here, which is not that each of these languages has something JS does, it's that Perl, Python, Ruby etc all support all the same features, have large ecosystems of modules, are easy to use, etc. JS is a fine language. It doesn't really bring anything new/different to the table (other than prototype inheritance, but that doesn't amount to much IMO), so the real differentiating factor is that it has a privileged position because of browsers.