Battery Health Issue

I repeat, two percentage points less does not make the difference, as the measurement of maximum capacity is done in charge cycles (1 complete cycle = charging from 0 to 100%, 1/2 cycle = charging from 50 to 100%, 1/4 cycle = charging from 75 to 100%, and so on), and obviously your colleague made less than yours.

Read this useful user tip:--> When to charge your iPhone or iPad - Apple Community

Regards

Giulio

have you read

About the battery and performance of iPhone 11 and later - Apple

Support

and maybe iPhone Battery and Performance - Apple Support

and Batteries - Maximizing Performance - Apple

That's normal, bearing in mind that that value is approximate (it might be at 98.9%) and, most of all, is related to when that battery (not the iPhone) was new.

Start worrying when the maximum capacity percentage goes down below 83-80.

Regards

Giulio

Thats nothing brother mine came to 89 in just 2 months