I am experiencing this issue with the latest non-beta iOS 18 and the newest public betas of iOS 18.5. I know brightness impacts it but to use it outdoors with sunlight, I know it has to be maxed both my iPhone 16 Pro and M1 Macbook Pro. However, this drain also happens with the latest updates and just doing simple tasks like browse the web or watch a video or write an email. I know when I bought the phone my battery life active usage was 12-14 hours and now I am lucky if I get 4-6 hours.
Wiping my phone to factory does not fix anything as I need my data and if you restore the phone from data backup, the problem just comes back. I cannot just give up all my data and only use Apple based apps for ensuring accurate battery life. Everyone uses apps like WhatsApp, TikTok, iMessage, Signal, Snapchat, FB/Messenger/IG, etc. Do not waste your time at Apple Store till after you get speak with Apple Senior engineers to try and fix the issue and give you authorization to get a free replacement at Apple Store. Apple needs to make battery life based on max brightness settings, watching videos on TikTok, and in different environments and temperatures.
Does anyone else still have this issue? I wonder when Apple will fix it and based actually battery usage based on 3rd party app and external factors.