My guess is that it is because not everyone is seeing that level of battery life. I have found in the past week, my mileage varies. One morning I took a screenshot where after 34 minutes of active use I was still at 100%. However, it drained quickly over the next 30 minutes. Some folks are seeing better than average life, others not so much.
Hopefully your excellent battery life continues. But remember, it can change and other's experiences can differ.