These "tips" from Apple are unfortunately not helpful. I upgraded from iPhone 14 to 16 pro, 16 is supposed to have better battery life but it is worse out of the box (like many other users reports on). I went from 80% battery on my 14 to 100% on my 16 pro and have worse battery capacity now. A bit of google maps and no social media, and it is down to 10% by dinner time.
A brand new phone user with a brand new fresh battery should not have to sit and adjust screen brightness to 5% or have their phone in low battery mode all day. These phones came advertised with "better battery life" and they are worse than previous phones.
It might well be a problem with iOS 18 which has been a quite daunting iOS to be honest since it is riddled with bugs and has barely no new usable features. I even have Apple Intelligence completely turned off by now.
I have reported this to Apple, in the meantime we can vent in this thread and maybe they are aware.