Probably the latter, but TBH the phone line almost never gets used...
Same here, but I have a couple of essential-use scenarios.
One is Mother Dear.
The other is that the mobile signal is so poor that voice calls often fail, so I have to ask people to call on the landline number.
I've had this issue with important calls recently, with the oncologist!
And if your ongoing deal continues to offer free line rental on ye olde aes cyprium line, then there's not much to loose, is there?
Can you make use of WiFi calling on your mobile? Now it seems to work quite well, I hardly notice if there's no mobile service, but I have WiFi.