To each their own. The privacy screen works good for certain apps or notifications. People like your sister will probably love something like this. I don't use privacy screen protectors, but I find the privacy screen handy and use it because, why not. No nobody asked for it.. Nobody asked for the Spen back in the day either, but now some get upset if it's not there. Will the privacy screen get popular in the future, I think it will and I think other manufacturers will adapt to it also.
I don't get this battery deal.. But just because YOU WANT it doesn't mean we all do or care. Some day it'll be here, but that's not today. Everyone screamed about no 60 watt charger capability and here we are with it on the phone. I never asked for it, but it is nice and gives a substantial increase in charging speed unlike the 45. So Samsung does listen, but it's never going to happen right away.