Most likely you have the Exynos CPU?
I upgraded from a S21 Ultra (Exynos) to a S23 Ultra (Snapdragon).
Battery life is so much better. I use the 80% battery protection option and nearly always make it through the day. Only if I constantly watch videos the battery is flat in the evening.
With power saving and 100% battery I can reach 2 1/2 to 3 days. Loving it.