My point is that while no one can tell you in advance that something will go wrong with an update, it is very unlikely that it will ever do irreversible damage to your phone.
Strangely enough, I had my first issue ever while updating my iPhone 6 to 10.2.1.
I was doing it through iTunes, which is unusual for me since I usually update over wifi, and an "unknown error" occurred causing the phone to freeze with the Apple logo and a partially complete progress bar. I then did a reset by holding in the power and home buttons, and I got the "connect to iTunes" screen on my phone even though it was still connected. Being at a loss for what else to do, I pulled the cable and reconnected. I was then presented with the options to restore my phone from backup or attempt to update again. I choose the update, and it completed.
My phone has been perfectly fine since. So even after all of that my phone suffered no harm.
Strangely enough, I had my first issue ever while updating my iPhone 6 to 10.2.1.
I was doing it through iTunes, which is unusual for me since I usually update over wifi, and an "unknown error" occurred causing the phone to freeze with the Apple logo and a partially complete progress bar. I then did a reset by holding in the power and home buttons, and I got the "connect to iTunes" screen on my phone even though it was still connected. Being at a loss for what else to do, I pulled the cable and reconnected. I was then presented with the options to restore my phone from backup or attempt to update again. I choose the update, and it completed.
My phone has been perfectly fine since. So even after all of that my phone suffered no harm.
