is my iphone 13 genuine? I checked the serial number on apple coverage website and it shows warranty for hardware

Although apple coverage show the details and valid purchase date which 17/11/2024 and warranty for hardware and technical support …I am still think that iphone could be not genuine because the battery which goes down rapidly although the capcity show 100% any help to make solid decision is this genuine iphone or not. I have used 3utools And showed normal staff and I checked the last value cycle count 3 from the analytics data which normal I believe.

Any help, thanks in advance