I am talking about quality and reliability. I don't have a landline phone at home, because reliability and quality isn't as important for households. It is important for businesses and will remain in use there.
It is vital for the military and government and will never be abandoned.
Where the telephone must remain stationary, or for someone who has difficulty using a cellular phone (typically someone very old), landlines will survive.
One security company now uses cell phones as its means of reporting residential break-ins because crooks can cut telephone wires.
The unreliability of a cell phone, other than failing to pay for the service, is failing to keep the phone charged. Communication on a cell phone can be very, very good.