That's why landlines are more reliable. Landlines are so inexpensive there is no point for someone on a fixed income not having one in home. If they are homebound even more reason than subscribing to cellular service.
Oh did you know. If you ever need to call 911 regardless if you have landline service or not 911 must go through if you dial it. Of course provided all the lines are connected. Even though I no longer have landline service I have a phone connected for that very reason when all else fails.