I'm not making anything up. As a lithium ion battery discharges, the max voltage available to the CPU lowers. For the first 80% of discharge, it's going to provide the nominal (average) voltage or higher. Most of that is going to be within a fairly steady plateau of voltage with minimal reduction. 20% or lower is when the voltage will start to drop off steeply and is logically the most likely time for a user with a healthy battery to experience voltage issues that could trigger Apple's throttling feature.
This link has the chart with the standard discharge/voltage levels...note the very steep/rapid voltage drop at 20% charge or lower. And like I said, that corresponds to Apple's low power pop-up in iOS.
https://learn.adafruit.com/li-ion-and-lipoly-batteries/voltages
Your are misinformed about how power management (DC/DC converters) and battery chemistry works work - please don’t post stuff that is not relevant/ incorrect.
Source: design DC/DC converters, senior IEEE member