In response to recent posts on this thread, I have just conducted an experiment. I watched a one-hour movie on Amazon Prime Video by streaming. It used 4% of the battery's charge. I then watched one hour of video from a downloaded movie; this also used 4%. If my maths are correct, to use 100% would take 25 hours.
For the record, I am using an iPhone 14 Pro Max on iOS 16.2. My display brightness is set at about 50% with Auto Brightness off. I had no other apps open (I always close apps as soon as I have finished using them). In Mail, I have Push switched on and Fetch set to 15 minutes. I do not have any social media apps on my phone.
I notice that iOS 16.3 is now available: I look forward to seeing any effect this update has on future posts to this thread, although personally I don't think the iOS is to blame for the bad battery performance some users are suffering. I agree with the clear, logical, well-informed contributions made by Dogcow-Moof.