Why do we need to use awaitTermination but not just shutdownNow()?

I am following the standard process that was recommended by oracle to shut down the executor services. here is the code that was recommended:

 void shutdownAndAwaitTermination(ExecutorService pool) {
   pool.shutdown(); // Disable new tasks from being submitted
   try {
     // Wait a while for existing tasks to terminate
     if (!pool.awaitTermination(60, TimeUnit.SECONDS)) {
       pool.shutdownNow(); // Cancel currently executing tasks
       // Wait a while for tasks to respond to being cancelled
       if (!pool.awaitTermination(60, TimeUnit.SECONDS))
           System.err.println("Pool did not terminate");
     }
   } catch (InterruptedException ie) {
     // (Re-)Cancel if current thread also interrupted
     pool.shutdownNow();
     // Preserve interrupt status
     Thread.currentThread().interrupt();
   }
 }

I read through the descriptions for shutdown(), awaitTermination, and shutdownNow();

I understand that
shutdown() only stop submitting new threads.

awaitTermination waits for the running threads to be shutdown. Returns a value if one of completed execution, time out or current thread interrupted.

shutdownNow() use Thread.interrupt() to interrupt threads.

My question is, if I know for sure that my threads only use sleep which can be interrupted by Thread.interrupt(). Is there still a value to call awaitTermination like what oracle recommended?

I know that shutdownNow() might have a chance to not shutdown a thread, but why can't we go ahead and do something like this to force stop the threads then see if there are still threads not stoped?

pool.shutdown();
pool.shutdownNow();
  try {
     if (!pool.awaitTermination(60, TimeUnit.SECONDS)) {
           System.err.println("Pool did not terminate");
     }
   }