> It feels weird to me, that classes were eventually introduced in JS.

if you don't put value in the Fraction prototype, then value will be created each time Fraction is instanced.

But that's not why class where created. Class simplify writing classes, doing inheritance and introduce "super" static binding which wasn't possible before with functions.

Also, JS will now force you to use new when instanciating Fraction class as an object. You can't call it like a function.