I've been a Verizon customer for 13+ years. Around Hanover, NH, it was the only option. However, they went from #1 to utterly useless. This all happened around the time they retired 3G. I have worked closely with members of Verizon's support team, including network architects. Ultimately, they said the cell towers here are working as designed. They didn't address the fact that the design itself is a absolute failure. No apologies, no discounts. I sit at work receiving texts that I can't answer. I waste a lot of time pressing refresh.
From my experience, this is 100% a congestion problem. Hanover, NH is a college town. Every day, starting around 9am, the service becomes unusable. This clears up a bit in the evening. There are random pockets during the day that it occasionally works (presumably kids are in class, or between classes, or whatever activity it is they use their phones less). During school vacations there are no service issues.
Why is Verizon so content with a system that doesn't work? Why aren't they upgrading the towers here? Why did they advocate to retire 3G when they didn't have an operational backup plan? Every day brings new personal frustrations. Every day seems to bring additional topics on this forum of exactly the same problem. Verizon, we don't want to work with support on an individual basis to try and solve the unsolvable. We want you to provide the service you advertise and we pay for.