One UI7 is only slightly different on these phones because of hardware differences. S24U is one year old, it's got a different CPU than S25U as well as camera hardware and built differences, which makes S25U slightly more performant than S24U, but put side by side they are not that different, especially since they both run Android 15 with One UI7. The Android and the UI makes some of the processing on the phones as it's noticeable. It's quite impossible to improve camera and battery on themselves unless the Android does some of the processing and optimisation from software alone. They are not twin phones though, and I don't think it would make sense to be twins, since they were released a year apart.
