Iphone 13, overheating and super fast battery drainage after 16.5 update

I have been using my iphone 13 for a good couple of months and was very satisfied with the overall battery life and cooling until i updated to ios 16.5,

ITS HORRIBLE. And i am not saying this with 0 context on the update or any attempts ate fixing my issues, i have tried for countless hours searching up ways to resolve this issue,

things you should know before you say its an hardware issue or i just need to “change” some settings on my phone:

1) i have changed every single setting in my phone for the most optimal battery life (background app refresh)etc

2)i have factory reset my whole phone completely like brand new. No backup as well

3) i used to shutdown my phone fully before sleep at 100% battery only to wake up and realize its battery had drained even while it fully turned off.

4) i have tried using multiple iphone original chargers. All with no improving results

i am completely frustrated that a barely used phone, which i use only 3 to 4 hrs a day has ended up not even able to survive that long without draining itself to death,

I CANT EVEN DOWNGRADE THE OS bcuz apple stopped signing the old ipsw,

one more important note, *my iphones battery doesn’t get hot, ITS THE A15 CHIP WHICH IS ALWAYS HOT, I suspect the os is unnecessary utilizing the chip causing alot of battery drainage, but i might be wrong,

still doesn't stop the fact that THE PHONE DRAINS BATTERY EVEN WHILE ITS FULLY SHUT DOWN.

And this is not a issue only i face, i have read multiple articles of people complaining about this and have seen a trend where its more common on the iphone 13. So please apple fix the OS