Why is 22 GB of data missing after transferring from iPhone 8 to iPhone 16?

Hello everyone,

I recently (within the last week) upgraded from an iPhone 8 to an iPhone 16. (This was a pain getting used to, as I miss home button; I have been using the virtual home button most of the time and it mostly does the trick, but I still miss having a physical home button. But, to get back on track here:) I have noticed that all of my data does not appeared to have transferred between the two iPhones. My iPhone 8 was using about 124 GB of its total 128 GB, and my iPhone 16 is only using about 110 GB of its total 256 GB. Apple Intelligence reportedly contributes about 8 GB to my new iPhone, and I have turned it off as I have no desire to use it; but I've heard that space only gets "reclaimed" for other storage once it is needed.

If my calculations are correct (to reference Doc Brown in Back to the Future haha), that means that about 22 GB from my iPhone appears to be missing. I have tried to compare how much storage certain apps are using on both phones to see where the differences are: most of the discrepancy appears to come from Photos and Messages.

If anyone has any ideas or helpful tips, I'd greatly appreciate it!! (I'm not planning to erase, give up, sell, or trade in the iPhone 8; I plan to keep it around as a backup just in case, partly because I'd only get $9 in trade-in value.) Thanks in advance!!

[Re-Titled by Moderator]