I don't think you are reading the list right. That is all the stuff that is encrypted both at-rest and in-transit (with keys known to Apple).
The list of E2E is further down, separate from the table, and includes: Home data, Health data (requires iOS 12 or later), iCloud Keychain (includes all of your saved accounts and passwords), payment information, QuickType Keyboard learned vocabulary (requires iOS 11 or later), Screen Time, Siri information, and Wi-Fi passwords. So virtually nothing, by comparison.
Messages, probably the most personal and relevant for legal cases, are end-to-end-encrypted as well, but if you have iCloud Backup enabled, the key is stored in the backup, making this useless.
If “backup”, photos, messages, contacts, calendars, iCloud Drive, notes, and safari data (and a few more) are end-to-end encrypted what else is there?