No it’s not irrelevant, to me it’s relevant. What’s funny is your implication that you think Samsung android models have magical batteries that don’t charging at the airport.
I avoid all of that I have an anker 22,000 mah battery. Never worried about topping off.
That's the point: you not needing to recharge your phone is still irrelevant in the bigger picture. For many of us who use their smart phone with all the latest and greatest feature, domotica, photography, videos, gaming and soon AR, it's just not enough.
I never mentioned Samsung. I'm only looking at Apple, and I still find their design choices strange to defend: making a phone thinner but allowing the camera to protrude while making the battery smaller with every cycle is problematic. Especially as what they're doing is so much harder: adding new power hungry features, faster processors and brighter screens while managing to maintain the same battery life with a smaller battery. It's marvellous that they manage to achieve all that! But it would be so much simpler to ALSO put a bigger battery in there.
Then you can keep that spare battery at home.