I am unsure fact will change whether you understand or not. These are test-based, science driven conclusions. You don't need to understand completely, and your individual evidence doesn't overwrite vast experiment and test done.
Power bank results aside. The poster makes a good point. Absent a bad battery or the USB, issues experienced by some, not me, I am in the same boat. Charge overnight. Charge in car when needed. Charge at office as needed. Even on business or personal travel where charging isn't always possible, never had issues needing battery swaps only saw wall hungers and never batteries being swapped out. It seems that those missing it the most are in the minority.
with rapid charging, why not charge it in the morning for half an hr instead lugged in all night long?
charging overnight would means the battery is near 100% all night, and high battery level/high voltage of the battery cell, is a negative factor for battery longevity.