Pretty standard option for any home with a teenager, to be honest. Long enough to drag the handset into the nearest coat closet when needed.

Mom’s listening along on the other phone with her hand covering the receiver.

We have them at work on our voip phones so we can roll around to each other's cubes while talking to a client without putting that client on speaker. We have headsets and the like too but you're not always wearing it when the phone decides to ring.