The answer is actually very simple and explained in the article below.
If you notice, when you buy a hard drive, they advertise it as 512GB but when you look in the OS, it's actually 476GB.
This is because, if you read the small characters, they calculate their GB using 1000 bytes multiplicator while in reality, it is 1024.
So if we do the math :
512Gb x 1000 = 512 000 MB x 1000 = 512 000 000 KB x 1000 = 512 000 000 000 bytes.
Now if we actually calculate the real space usage as computers calculate it we do :
512 000 000 000 / 1024 = 500 000 000 KB / 1024 = 488 281 MB / 1024 = 476 GB
In the Samsung app though, you see storage space being 512GB, not the real size of 476GB (most likely to avoid regular user confusion) so to compensate for this missing space, they add up that space to the system category. In this case, 512GB - 476GB = 36GB meaning the actual OS and system files take 22GB total.
The smaller the drive, the lesser the difference. Which is why it looks like system takes less space on a 256GB phone than it does on a 1TB phone.
Recently there have been reports that One UI 5.1 reserves upwards of 60 GB storage for system partitions on the Galaxy S23, Galaxy S23 Plus and Galaxy S23 Ultra. Samsung may continue to insist on pre-installing third-party apps on One UI, but claims of 60 GB in bloatware are far from true.
www.notebookcheck.net