Battery
Why My Iphone 13 battery draining so fast ?Is this coz of update ios16?
iPhone 13, 16
Don't worry about it. That's an estimate, to begin with. Secondly, it's normal for the battery health to drop with time and use.
You'll see it plateau at some point too, more than likely.
You'll lose an average of 1% per month of use, but that's just an average. Sometimes it will be more, sometimes less.