Actually you are incorrect.

There's so many factors I can't even begin to cover the list. But there are a few major things that definitely can affect the signal around a certain area. Let me cover this first and then I will go farther into this debate...

Area: The area of which the customer is located can determine the signal quality. For example customers on a mountain or in the area of a mountain can defer the signal because of the elevation. Plus, you have to consider foliage too. Trees, shrubs, bushes etc can also block signals. Water is probably the biggest problem. Anyone who lives on water or even within a few miles often have issues with cell service because the water acts as a diffuser.

Buildings: This is probably the most controversial part of network coverage. This depends on the year built, the type of roof (shingles or metal) plus the siding (metal or wood or plastic). Also, you have to consider that some buildings use concrete and bricks which cause the signal to not be able to pass through. For example, my mothers house is in a high residential area (easily over thousands of residents) however because of the small pond in the backyard, plus the woods and tall trees lining the property plus how the house was built and renovated, I am unable to get any or very little service inside the property. However as soon as I leave, I am able to get full signal.

Device: There is sometimes updates that are included in Software Updates that can help with signal issues. This is why it's important to keep your device up-to-date. Older devices aren't able to keep up with new ones (duh).

Note that VZW literally has no control over any of these.

It is resolvable. It's up to the customer whether they want to take the 20 minutes out of their day to report a problem. It's not gonna happen immediately.