Samsung reset mine after I lost the password (long story). I was able to prove it was mine because it still responded to “find my device”, they would not reset the lock screen, but where OK with a complete reset back to factory, which was OK for me as I only used it for media and email. And any data was in gdrive.
During any update, apps are “optimized,” which deletes any unnessacary cache files, and so system size can reduce after any update.