Because the reason you can hear people now, is because they own most cell phone towers in the US. The other just rent space on them, typically.
Also, verizon is the largest prepaid cell phone company. Others, like Straight Talk, or Netspend (other large prepaid companies) USE VERIZON TOWERS.
That’s exactly why I use Straight Talk. Same coverage as Verizon, cheaper than Verizon and no contract.
Now I see why...
You can add TracFone to your list.
For over a decade, my wife and I probably caused severe head injuries with the NSA staff from going to sleep listening to our messages like, we got there ok. Do you need anything from the store? I will be late due to a wreck.
We had a TracFone for over ten years and never came close to using our paid minutes. With messages like the above.
This year, we have two Tracfones as per requests from family members to start texting. Our texts are even more boring and possibly more dangerous to any NSA listener.