Well, he can read. You can't. So you should be a little jealous.
3 days, 6 hours screen on time. That is far from "not using your phone"... you can see a good amount of that was Facebook. He is obviously a social person. Also, that app SUCKS battery - even more impressive is the fact the device survived 3 days of standby whilst running that app and having the display on at least 2 hours a day. I would define it as pretty medium/average use. 2 hours a day on your device is pretty intense use and at the very least not anything you described as "barely using it" ...
Never seen an iPhone go 3 days on standby, with that kind of screen on time. Hell, I've honestly rarely seen any newer android devices go that long with that kind of display on time. It is slightly impressive, yes.
i did calls, mails and used texting app because i dont have text plan but all of them are only 2% below and i didnt know that i had to show the rest of them