Depends what you think of as ‘most’ really, things that don’t have end-to-end includes photos, icloud drive files, notes and backups.
https://support.apple.com/en-us/HT202303
[1] https://support.apple.com/en-gb/guide/security/sec1782bcab1/...
On a mobile device chances are your passphrase is rather weak because it's tedious to enter.
Depends what you think of as ‘most’ really, things that don’t have end-to-end includes photos, icloud drive files, notes and backups.
https://support.apple.com/en-us/HT202303