Probably Apple's way to "fix" battery life - give their users an illusion of good battery life by making the usage go up in standby 🙄 Most idiots look and think "wow! 10 hours usage!!!!" even though there is no chance they ever used it that long in a single day anyway 🙄
I much prefer Android's "screen on" time, can really see the effective usage you are getting out of the battery since almost all tasks require the screen to be on - except music which just skews "usage" stats anyway.