Depending on your house setup you might not be able to. My washer and dryer are in my basement, and I can't hear them at all (neither when they are running, nor the sound they make when they finish). Moreover, the timer listed on the machine when you start the cycle is not accurate (particularly for the dryer, which is frequently off by 30+ minutes). This means that I have no idea when my clothes are done except by going to the basement to check. That's not the end of the world, but it would be genuinely nice to be able to get them on my wireless network and have them send me a notification.

Perhaps that doesn't apply to you and how your home is set up. Fair enough. But that doesn't mean the use case doesn't exist.