Confusing usage of AthenaSensor?

As per the various blogs on AthenaSensor, the usage looks like:

  task1 = AthenaOperator (helps querying on aws athena.)
  task2 = AthenaSensor (waits until task1 is completed.)
  task3 = PythonOperator
  task1 >> task2 >> task3

However, in case of sequential executor, only 1 task can run at a time. We can specify the order of execution of tasks using Bitwise (<</>>) operators, which means task3 cannot run before task1 completes.

So, is the need for AthenaSensor redundant? What’s its use?