Why can't the engines support both at the same time? One is syntactic sugar over the other. I see libraries providing dist files for both and node refusing to

Why can't the engines support both at the same time? One is syntactic sugar over the other. I see libraries providing dist files for both and node refusing to run if you don't name your file one way or the other and it seems like a fight over something without distinction. As ridiculous as having to decide if you can only use while loops or for loops. Support both.