Understanding parameter options

You've used a few different methods to add templates to your workflows. Considering the differences between options, why would you want to create individual tasks (ie, BashOperators) with specific parameters vs a list of files?

For example, why would you choose

t1 = BashOperator(task_id='task1', bash_command=templated_command, params={'filename': 'file1.txt'}, dag=dag)
t2 = BashOperator(task_id='task2', bash_command=templated_command, params={'filename': 'file2.txt'}, dag=dag)
t3 = BashOperator(task_id='task3', bash_command=templated_command, params={'filename': 'file3.txt'}, dag=dag)

over using a loop form such as

t1 = BashOperator(task_id='task1', 
                  bash_command=templated_command, 
                  params={'filenames': ['file1.txt', 'file2.txt', 'file3.txt']},
                  dag=dag)