Have the same issue, iPhone 16 Pro 256g, after install started phone shut off now I'm getting dead battery screen, when you plug in to charge just low battery screen, can't force reset. I was at 70% battery and plugged in while the update was installing. Now the phone is bricked.

plug it into MacBook (If you have one). quickly Volume up, then down then hold the power/lock button for 10 seconds once the screen goes and the low batter screen goes black keep holding down the lock button then also hold down the volume down button for another 5 seconds. https://www.youtube.com/watch?v=kaRpv3sjaHU this allowed me to reset back to factory