I already carry a power bank with me when I know I will stay long away from home. So in some way, one does not need to pay apple for that. I also know people who carry some monster phones with them with huge batteries that last for several days, but I would rather carry a power bank than forcing the extra weight in my pocket.

Also, with android you have more options to optimise for battery life (eg low refresh rate and resolution) that are great if this is what you want to optimise (and did this for some time), but apple would never sell an iphone like that, and also ime these are becoming rarer in the android market too. If the sole alternative is just bigger batteries, I would rather not have this bigger battery attached to the phone all the time even if this is suboptimal for some other reasons.