Don't worry. It's completely normal. The reason why the S23U is lasting longer is cause of the chip on that is a Snapdragon 8 Gen 2. While this chip has been out for a while, samsung almost optimized that chipset for their S23 series. So according to that the new S24 series comes with the new chipset S24U, which makes the chipset needs to be optimized for the apps and it's overall usage.
For that to happen it might take some time, cause the new chipset is literally a power house but still is being optimized by their latest updates. It should be getting better and better battery life with upcoming updates. It's recommended to use adaptive battery protection feature for a longer life span of your battery! Regardless just wait for their major updates and everything will be fixed.
