Verizon's wireless network is reliable and CTO Kyle Malady intends to keep it that way by enlarging capacity for unexpected changes. The chart at left shows he has more than doubled "capacity margin" despite capex being flat to down since 2013. 

(Among other things, this means Verizon has the capacity to bring 25 Mbps down, 3 Mbps up to at least two to three million currently unserved school kids. Probably more.)

Chess Grandmaster Aron Nimzowitsch introduced the idea of "overprotection" in his classic My System. Nimzowitch recommended protecting an important pawn or square more than is apparently necessary. Your opponent may surprise you and need the "over" to respond.

The pandemic is the greatest network disruption since the explosive growth of the iPhone brought AT&T's network almost to its knees. Wireline traffic went up ~30% in a few weeks, more than a typical year's increase.

There was no slowdown customers would notice in fiber, DSL, and downstream cable. Upstream cable was > 90% of promised speeds most of the time but occasionally stretched. It's time to improve the upstream. Fortunately, the technology for 100 Mbps upstream cable is now reaching the field.

There was almost no practical impact on users; any article saying otherwise was wildly exaggerated.