I read an article about the battery management being very different for 14.5 and that is it recalibrating on certain newer phones. While this isn't relevant directly to the SE, it might have more to do with the changes of that management system that is impacting your visible charge level. For the 11 and up is said it would take about two weeks to "recalibrate" so see how your phone is actually handling it in two weeks to see if it is just getting the levels right.
Personally I haven't seen my phone lasting longer but I'm normally sitting with it docked on my desk during the day and only "mobile" for the latter half of the evening when I'm using my iPad mostly.
Louis L'Amour, “To make democracy work, we must be a nation of participants, not simply observers.
One who does not vote has no right to complain.”
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