The implementation of the method Collections.sort(List l, Comparator) should be implemented as follows:

    @SuppressWarnings({"unchecked", "rawtypes"})
    public static <T> void sort(List<T> list, Comparator<? super T> c) {
        list.sort(c);
    }

and the default implementation in List.sort should be the previous implementation of Collectors.sort:

    default void sort(Comparator<? super E> c) {
        Object[] a = toArray();
        Arrays.sort(a, (Comparator)c);
        ListIterator<E> i = listIterator();
        for (Object e : a) {
            i.next();
            i.set((E) e);
        }
    }

Thus ensuring that Collection.sort will use the most optimal sort implementation provided by the list implementation.