@tsarstepan,
I live right outside the city of Annapolis, and because of all the waterways, streams, rivers, creeks the County never installed public water systems. We also are susceptible to power outages because we are on an old fuddy duddy grid that won't be updated in my lifetime because only the new housing developments and businesses are hooked up to the more modern 19th century systems.
When we lose power that means no water, and no flushing capabilities and no recharging of cell phones. So, landline is something we are not yet willing to give up.
We also get robo-calls on our cellphones, but only once or twice a week. That pales in comparison to the multiple calls that come in on the landline....but still irritating.