The only time I had to hard reset the phone was when I wanted to stop it updating itself. It's quite tricky, you have to do things in a certain order, quickly after the startup, to accomplish this and disable "Software Update" and a stack of other things.
Before I reset it, it was slower. The slowing down coincided with the appearance of the "Oreo is now available" prompt. It doesn't have to be updated, the phone merely seems to need to know that an update is available and the device then starts slowing down. I could reproduce this with several resets noting this each time.
Unrelated, since the phone doesn't now update - the phone does get slower with use and benefits from an occasional reboot to restore performance. You might call this slowing down "lag" because it makes the phone seem latent to respond to presses and actions. However to answer your point: it does not need a complete reset to "fix it".
Having had the phone since January 2018 I think it's pretty much identical now to how it was out of the box. It should be since it is identical, the OS software is as shipped and I think they got the S8 and Android 7 pretty much right in the first place.
10-19-2018 05:33 AM