Well, i'm jumping in here as i've several phones and manage devices in our company as well- just again, it's my personal experience or the experience i got from co-workers- everyone uses their phones differently- mostly for work, with a set of pre-installed Google Apps. Usually it's an all-day mix of calls, videoconferencing, chat and mails.
We have mostly iPhones 16 Plus (on iOS 18 and 18.01), iPhone 15 Plus (on iOS 17.7 and iOS 17.4.1) and iPhone 14 Plus (on IOS 17.4.1 and iOS 17.7).
Right now Users are happy with iOS 18.0.1. I don't get to much complaints about Battery life- but also, those phones are fairly new.
iPhone 15 Plus Users partly complain on 17.7 but it seems better than the Versions before, i get less complaints on 17.4.1.
iPhone 14 Plus Users on iOS 17.7 complain a lot, those who are on 17.4.1 are happy so far- but those devices are "old" now.
Personally, i'm on an iPhone 15 Plus with 17.4.1, Produced in Oct 2023, first Use in January 2024, 86 Cycles and Battery down to 99%. I couldn't be happier with my battery life, i usually travel a lot, spend most of my workday on the phone and still get through 1,5 day.
I think it's really about how you use and charge your device- a colleage with about the same time has over 240 Cycles already and the battery is down to 94%.