You could try all the same things I tried described in this thread.
Go the scientific, methodical, route - measure everything. Duration, from how many % to how many % battery in that time, take screenshots. Every time you change something, give it a few hours until you're confident it changes either something or nothing. Then switch it back and try the next thing. Yes, this will take days, if not weeks, but keep a record of everything you do and the result. As you can see I built quite a record and detailed descriptions of what was going on, including screenshots of the battery drain at some points (I have lots more but didn't want to spam too much here). In the end I could with absolute (or at least 99.99%) certainty show that the problem was in the phone, not any of my apps, my usage pattern, my charge pattern etc. etc. When the evidence is irrefutable then Apple has no option to swap it. Otherwise they can* keep sending you back into the weeds with "have you tried ...".
You may not have to go this far. Maybe all it takes is a simple call to Apple Customer Support and mention your phone drains like crazy and they'll replace it. I may be the weird one, but I like to come prepared to the battlefield 😝 If you're close to an Apple Store maybe you could pay them a visit (closest to me is a 2hrs drive away) and have them take a look at it (I doubt they'll replace it on the spot, but you never know). If you have AppleCare+ then Apple may be even more willing to replace it quickly or without too much asking. However, you do have a right to a decent working product which you paid (dearly) for. So if the phone doesn't do what it's supposed to do or doesn't function as it's supposed to function or doesn't last as long as it's supposed to last then - in most, if not any, part(s) of the world - you're entitled to (most) of your money back or a replacement. It depends on where you live (I'm in Europe) so your mileage may vary. But I'm sure Apple will be happy to replace it if it's actually a lemon (production error).
Having said that: how long does yours last and could you post a screenshot like I posted which clearly shows a) the green battery usage graph and b) the blue activity graph? If you have any means to measure temperature reliably, like I did, then measure the temperature after your phone being "idle" for, say, an hour (with no apps open or anything) and also, or especially, at times when it's hot. Note down what you were doing what (may have) caused the heating in your opinion. Again: measure, build a record. The first thing you're gonna have to do is define what you mean with "battery is draining hard"; what is 'draining hard' in your book may be 'normal' in someone else's book. Numbers. Durations. Graphs. Cold hard data.
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* Not saying they will.
