I’ve had an iPhone 15 Pro Max since October 2023. I’m happy with it and would like to use it for a few more years.
One thing bothers me a lot. The battery consumption of the apps and the fact that it keeps freezing and getting really hot.
According to the check, the battery is in normal condition and at 84%.
The memory is only half full.
What could be the reason for this?

Is that saying that the Mail app is the largest user of your battery? That would seem odd; do you use it a lot?
Not really. Two times these day.