How long will 'ongoing device setup' take on my new iPhone 16 Pro Max?

I have just purchased the 16 pro max and noticed the battery life has not even lasted me 24 hours. I went to the battery settings and saw the “on going device set up” notification. It says the iPhone is completing set up steps in the background and that battery life may improve once finished. What does this mean and how long does it take for this notification to disappear ? What settings is it still finalising?

[Re-Titled by Moderator]