If unplugging your charger at 100% and letting your battery run to 84% or whatever, and then plugging it back is so good for it, why doesn't Apple (or any other laptop manufacturer) just have the power controller do that automatically when your laptop is plugged in?

I call malarkey on all of it. I've had my laptop plugged in for years and it sits at 100% most of the time. I don't have time to deal with that kind of hassle, even if it is true.