So recently I undertook the tedious task of updating all my apps and software ( 1 hour of my life I won't get back ). As a general principle, if a app still works for what I need it for then I don't update is or jump on the latest trendy features that have been rolled out but for once I decided to forgo my own principle and I realised in the ensuing days that somehow my battery life and charging time had become drastically different. My battery takes 3 times as long to charge now and half the time to deplete from before the updates. Now I'm not one for conspiracies but I have heard it said that phone companies embed software that compromises the phones lifeshelf for the sake of forcing consumers to buy their more newer phone models. And this definitely seems to be what's happening to me. I've had the same phone for over 4 years and it's worked flawlessly for everything I need it too but now, I'm considering doing a factory reset just to undo whatever has been done to my poor ol' reliable A10s. Basically I'm ranting but I'm sure any of you can learn something from it, lesson being... consider it carefully, if you really need to make updates.
Actually, doing factory reset won't undo the system update. Secondly, your phone is not even new (if it was, I would have compromised). You've been using it for four years; meaning, it has been through a lot (including using different chargers, falling, consumed while charging, installing games or storing huge data...) all these decrease both phone and battery quality. Therefore I see nothing wrong done by Samsung manufacturers. No offense 🙏🏿