This is in the same vein as the question "why would I want a web browser on my phone? Why wouldn't I just use the web browser on my desktop computer?"
As to why you'd want a device that is listening - and does something when its triggered - is that you can arbitrarily activate it with your voice. For example, if your hands are full, or dirty, because maybe you're cooking or changing the oil in your car, or cataloging the stuff you have stored in your garage.
It doesn't take too much imagination to see why Amazon would invest in creating such a product.
As to why you'd want a device that is listening - and does something when its triggered - is that you can arbitrarily activate it with your voice. For example, if your hands are full, or dirty, because maybe you're cooking or changing the oil in your car, or cataloging the stuff you have stored in your garage.
It doesn't take too much imagination to see why Amazon would invest in creating such a product.