As someone who has caught a postman who damaged my car because it set off the alarm and alerted me before he could get away I think they can definitely be beneficial

I always keep my ears tuned for it, also using the panic button can be handy.
Never had an issue with an alarm being too sensitive either, simply had any aftermarket ones set correctly and the OEM ones have been fine (only time I had an issue was when the interior motion sensor was defective, it was replaced under warranty).
In the end I determined that it is a lost cost option that does have its uses making it worthwhile.