iPhone 14 stopped working altogether doing upgrade to 18.1

My phone, plugged into iTunes, and updating to a new iOS version froze. The Genius Bar told me an internal part was "fried" and it would cost me $400 to repair it. Yes - I'm stupid - i do not have insurance on the phone. My carrier (V) or Apple would help me, in the sense I still owe $400 on the phone to V, and repairing it at $400 would make the overall cost of the phone $1200.

What I am most interested in is whether anyone else has seen a phone "fry" when downloading a software update? I am very trusting of experts but cannot understand how this could happen. Phone has been cared for very well and is in pristine condition. Something just happened.