New iPhone 12 battery drain issue

Recently bought iPhone 12 and I'm not happy with the battery backup. I have disabled lots of features and in spite of that, backup isn't great. Biggest problem is battery drain overnight being idle and has been noticing that it drains more than 15-16%. I have been using iPhones for the last 10 years now and have never faced an issue like this. I'm not happy with my new iPhone 12 and I need an immediate resolution. I'm on iOS 14.2