I think you're both ignoring the more interesting part of this: That it also powers the landline phone. Powering a landline used to require either a utility connection or a line simulator to provide the correct voltage. It also provides a dial tone and allows you to use a rotary or touchpad dial.

Pretty cool invention to pair bluetooth connectivity with a line activator.

(Also: landline telephones, for the most part, are built much sturdier than a cell phone. It's a way to keep well made hardware out of landfills by modernizing them. They are bulkier than cell phones but a nice phone for home - or, for humor - for your car.)