Is it correct that iCloud backups can lead to officials being able to unlock your physical device? That’s not consistent with my understanding of Apple’s circle

Is it correct that iCloud backups can lead to officials being able to unlock your physical device? That’s not consistent with my understanding of Apple’s circle of trust implementation. I get that the backups can potentially be compromised, and of course having the backup means having most of what would be on the phone, but I would love to know more about how having a copy of a backup can compromise the physical device via iCloud.