That is still "docked" in the data sense. If you are more than 10
meters from the house phone, it is a paperweight.
As long as everyone has their own phone that is OK but if you are home
alone and don't have a phone you are Amish.
I suppose you can back that up with VOIP but at that point, why bother
with the cell interface?
If you don't have a cell phone you are correct, but this day who doesn't? If you are home, you can use your "home" cordless phone to make and receive calls. If you are away, you have your cell phone with you.
For some that may not make sense, but for many (most?), it works great. We only keep out landline for the home alarm reporting service. One day I'll get an internet phone service and get rid of the TW bundled phone. It's just not that much money or big of a deal to make it worth it right now.
So this thing responds to any cell it is mated with (more than one)?
How does it decide which one to use with an outgoing call?