The phone, no. If there is a properly executed warrant for iCloud data, Apple will cooperate by giving access to that.
That’s different from on device security, which Apple has no ability to break.
One major caveat with this, as I understand it anyway, is that iCloud backups aren't end-to-end, meaning law enforcement can effectively access your entire device if they gain access to your iCloud data through Apple. For example iMessage is E2E encrypted but the messages are readable in plain sight on your device backup?
Many privacy-savvy users avoid iCloud backup for this reason and make encrypted hard backups to their Mac, which in turn uses an encrypted Time Machine disk to backup its own data. Very happy to be corrected, or updated on current affairs if something has recently changed ?