Asynchronous in dart

Question

On Dart DOC site I see this example of asyncronous,

    Future<void> printOrderMessage() async {
  print('Awaiting user order...');
  var order = await fetchUserOrder();
  print('Your order is: $order');
}

Future<String> fetchUserOrder() {
  return Future.delayed(const Duration(seconds: 4), () => 'Large Latte');
}

Future<void> main() async {
  countSeconds(4);
  await printOrderMessage();
}

void countSeconds(int s) {
  for (var i = 1; i <= s; i++) {
    Future.delayed(Duration(seconds: i), () => print(i));
  }
}


// output


Awaiting user order...
1                       // after 1 second
2                       // after 2 second
3                       //after 3 second
4                       // after 4 second
Your order is: Large Latte  // after 4 second

after I changed the code by convert return type of printOrderMessage() and main() to void and remove async and await of main() , is output the same result

 printOrderMessage() async {
  print('Awaiting user order...');
  var order = await fetchUserOrder();
  print('Your order is: $order');
}

Future<String> fetchUserOrder() {
  return Future.delayed(const Duration(seconds: 4), () => 'Large Latte');
}

  main() {
  countSeconds(4);
  printOrderMessage();
}

void countSeconds(int s) {
  for (var i = 1; i <= s; i++) {
    Future.delayed(Duration(seconds: i), () => print(i));
  }
}

// output

Awaiting user order...
1                       // after 1 second
2                       // after 2 second
3                       //after 3 second
4                       // after 4 second
Your order is: Large Latte  // after 4 second

Why we ever need to sync and await in main() and return type of Future, if show the same result ?