I don't know that that is true. Perhaps iPhone allows users to draw down the battery even more than competitors to preserve someone's "on"-time (like extend as

I don't know that that is true. Perhaps iPhone allows users to draw down the battery even more than competitors to preserve someone's "on"-time (like extend as much as possible, because you might be on an important call), because it knows that once plugged in, it can go into a dark state for some time to recover. If the choice is to have a stable power mode when on / under potential loss of AC charger power, is it unreasonable that Apple chose to do that? Are you certain that's not why they do it? Maybe other phone manufacturers are cutting off your "on"-time sooner than iPhone is, and you just don't ever see their phones getting to this state. You don't even get to make your 911 call, because Samsung chooses to turn your phone off sooner? So again, in that case Apple would be giving you more usable time, but you're not happy with them for it.