Still does not really explain why my 4S suffered from both after an iOS update: Reduced screen-on time and degraded performance at the same time, that was a cou

Still does not really explain why my 4S suffered from both after an iOS update: Reduced screen-on time and degraded performance at the same time, that was a couple of years ago tho. As a user, it's just utterly baffling how apps that used to work fine suddenly became near impossible to use, like messaging apps taking ages to type a word, the phone felt like a computer with too much bloatware running in the background, struggling with the most mundane tasks. Since that happened I've been putting off installing the iOS updates because this degradation in performance, after an iOS update, has been way too common of a theme over the years.