I get what you are saying and truth to be told 6 hours of battery drop sounds like too much and would bother me as well, but for that dramatic battery drop I wouldn't blame iOS and iPhones in general but will look for a different reason. I am very confident to say that, because I bought my 15PM in November and before I was running betas on my 12PM, which was on 91% of its original capacity and had it for approx 3 and half years when I switched to 15PM. The battery was getting me through they day and true I ended up on 10-15% of battery when I went to bed, but for a 3 and half years old battery, I was OK with that.Battery degradation is not what I'm talking about. What I'm saying is that I magically lost half of the battery life I used to have on iOS 15 and 16 by just upgrading to iOS 17.0 beta 6 or 7 I don't remember at this point. It was sudden. It was just one update and boom. I patiently waited for 17.0 RC, then for all the 3rd party apps to be updated (even though I knew that won't help) and guess what? That didn't help. And we're at 17.4 and it still the same.
Also, even if my battery was at 80% health (it's not), I shouldn't have such a major decrease in battery life. 1-2 hours is understandable, but not 6 and not after one iOS update.
I'm not on beta since 17.3. Well actually the only "beta" I installed lately was 17.4 RC.
Of course it was big and heavy from the day one. But I don't like to bring a powerbank with me, that's why I decided to buy a Pro Max iPhone.
What I'm trying to say is that with iOS 17 this phone is big, heavy AND has the battery life of an iPhone 13 mini.
If SW updates didn't work for you, I would try more dramatic solutions. Do a backup, wipe out your phone, set it as new, restore from backup and keep only most critical apps on your iPhone first, offload the rest and you should see if that makes any difference.
EDIT: What I was saying, is that you may have bad luck and the update to iOS17 did something that was juicing your battery on the background. I guess, you checked the stats of what app was taking more juice than usual, but you didn't mentioned it in your post, so I am just curious.