Battery issue on iphone 12 pro max

Its been more than a week and the issue is still there, in-fact it drains faster now

Are you talking about your battery health going down or battery charge level?

If you go to Settings, then Battery and scroll down a little, you’ll see what’s using your battery. Sometimes it’s just people on their phone more because they want to check out the new features or maybe you have a rogue app that’s draining your power. I just looked at mine for instance, and it’s showing Facebook using a lot of battery in the background. That probably means I need to turn off background app refresh on Facebook.

Yup it’s common for battery drain after an update. Give it a week or so

He is talking about health draining which is pretty concerning than simple battery draining.

I’ve also heard about this after iOS updates. It’s nothing new I think maybe due to recalibration. I doubt the iOS update can physically damage hardware.