An X Box reinstall mystery

I recently reinstalled the sim on my XBox X. At first I only installed the base sim. I didn’t install the offline mode or either Premium or Deluxe upgrades and no 3rd party addons. To my understanding the ‘Reserved Space’ should have been only the amount for my profile which is just over 3 MB but yet it was 16 GB.

Does anyone have any idea why it was 16Gig? I can imagine maybe the game sets up its Rolling Cache so that could account for 8Gig but whats the other 8Gig?

Have you seen this on your XBox or am I the only one?

I’ve since installed the offline mode and some 3rd party stuff and a few select items from the Premium and Deluxe packages so the Reserved Space is higher now but Im curious why it was 16 Gig when I did a fresh reinstall.