I have Verizon and there are far fewer issues with them than other providers here. When I was working, our corporate owners were changing cell providers almost yearly. We always had issues with service in the Sierra Nevada when we weren't Verizon. Our crews figured out how to force the non-Verizon phones onto the Verizon system when there was no other service. Corporate tried to block that but our local HR finally stepped in and said this is a safety issue, so either let us switch to Verizon, or stop blocking access to it. Corporate finally gave in, but for us only. Our 63 other locations remained with other carriers.
My wife has family in St. Louis, and near Grayville, Illinois. I can't tell you how many times we traveled on Interstate 64 over the years and always had service with Verizon.