not happy with IOS 26 battery performance

Since Apple published IOS 26 to public, and my IPhone 16 battery which is now 20 cycle and 100%, performing not so good at all, it drain quickly and I surprised one day with very light use like some camera and phone calls dropped from 80% to 10% in just 6 hours of very light using, and even turned on low battery mode on 10%, what happening on IOS 26, I really want to get back to IOS 18 but I don’t have any backup.