I limit my laptop battery charge to 80% with a third party software tool. Laptops can generally bypass the battery and directly power themselves from the wall.
Does this new 80% battery limit setting imply that the new iPhones are able to do the same? Implication would be less battery wear while docked on a desk/in a car or due to long “AAA” gaming sessions, since it will draw power direct from the wall rather than using the battery as a middleman.
I don’t have an iPhone and don’t really know what goes on inside of them, but on my 2018ish Android phone battery passthrough / battery idle isn’t supported because it lacks the required hardware to do it (take a look at Advanced Charging Controller if you’re interested in this for your Android phone). Old iPhones may not have that circuitry either.