iPhone 13 battery replaced still dying just as fast

I had my iPhone 13 battery replaced nearly a week ago. Battery health says 100%, however I notice the phone still does just as quickly. I have an old XR I also use, and I noticed that battery lasts way longer even while doing the same things on the phone. However, my XR battery health is 85%. Can anyone make some sense of this to me? I had my iPhone 13 battery replaced at Apple directly so true parts were used. My 13 is all up to date with updates as well.