I'm a little confused by what you're asking.

Can you give an example of a use case where we would need to queue the results of asynchronous tasks?

Usually, we choose Celery because it can process work in the background, and we don't care when the work gets done.

Whether it's 1 second or 5 minutes from now, Celery can just write results to the database or cache and we'll use them later once we need them again.

You might have Celery send an email or queue up some other type of notification to let the user know when the job has finished, but that could happen within the Celery task itself.