That spec stated above is the minimum requirement. If the battery ends up at 80% capacity after only a measly 500 cycles then it meets its specification.
BTW, being at 80% after only 500 cycles is abysmal performance. It shouldn't hit 80% even after 2000 cycles if you take care of it
That answer reads a bit too much like misinformation to me. Most people charge their phone at night. They should go through < 1 cycle per day. Would you expect their batteries to retain 80% at 5.5 years (a little less than 1 cycle / day). Also how do you justify attributing variance in battery life almost entirely to customer behavior?
What constitutes taking care of it?
The typical guidelines are:
-don't discharge your battery to zero,
-don't operate your phone in environments with extreme temperatures.
Apple and other phone manufacturers may avoid allowing their batteries to truly cycle to 0% to prevent long term damage. Beyond that, if you aren't using these things in extreme temperatures, how much impact do you really think you personally can have on their lifetime through easily controllable actions? You are unlikely to get a factor of 4x from this.
TLDR,
don't mislead people
