I run phone repair shops and the app starting up slowness is often caused by a failing battery.
In fact, at our shops, on older iPhones, I can test the battery state by opening the camera app. If it takes 10-20 seconds to open, it’s usually the battery causing it. (The other cause is storage being close to full.)
This won’t help the app resetting issue, which the author correctly identifies as a RAM problem (that I also encounter on my personal iPhone 13 Pro. Apple is horribly stingy with RAM even on the Pro models.)
In general, if you use your phone daily, I recommend getting the battery replaced every 2-2.5 years.
Remember how people laughed at Windows users and the Windows OS? That you have to reboot daily or else it slows down?
Well, these days, my Samsung flagship actually pops up a notification every once in a while, reminding me to please reboot the phone to ensure smooth operation. There's even an option you can turn on to make it automatically reboot every night!
(I imagine that option doesn't automagically skip the SIM card lock and the Android security lock, so IMHO running it is insane, as it would make the phone unreachable until you wake up and unlock it properly.)
In fact, at our shops, on older iPhones, I can test the battery state by opening the camera app. If it takes 10-20 seconds to open, it’s usually the battery causing it. (The other cause is storage being close to full.)
This won’t help the app resetting issue, which the author correctly identifies as a RAM problem (that I also encounter on my personal iPhone 13 Pro. Apple is horribly stingy with RAM even on the Pro models.)
In general, if you use your phone daily, I recommend getting the battery replaced every 2-2.5 years.