Bandwidth does not equal monthly usage.
If Verizon said "we want to implement a time-of-day based surcharge to help reduce network congestion", we could reasonably discuss the merits of using financial rather than technical means of throttling heavy users.
Charging me per GB of 2am Windows updates, however, counts as nothing short of rent seeking via regulatory capture. Every single unused bit of capacity of my nearest cell tower gets wasted forever. It neither costs Verizon more, not saves them a penny, to ever have a tower sitting idle; and thanks to a complete (intentional) failure of the FCC to properly allocate spectrum as a public good, you and I can't simply say "screw you, Verizon, I'll put up my own cell network!"