Not necessarily.

I'm an IT admin at work and while Jamf is installed on every computer we can't do that without a users' consent. Apple has also been pretty serious in later macOS versions making sure the user allows ”screen recording”. This isn't something that (to my knowledge) can be worked around by IT.
No control over a personal iCloud account just because we have control over some aspects of the computer.
I asked ChatGPT if a Jamf admin has any control over personal iCloud data
”No, as a Jamf admin, you do not have direct control over a personal iCloud account that a user has logged into on their Mac. Jamf primarily manages the device and its settings, apps, and configurations, but it doesn’t grant access to or control over a user’s personal iCloud account.
What Jamf Can Do:
• Device Management: Jamf can manage settings, software, profiles, and configurations on the Mac itself, including enforcing security policies (e.g., password requirements, encryption).
• Application Control: You can control what apps are installed on the Mac or push apps to the device, but you don’t have access to user-specific app data (like files stored in iCloud).
• Restrictions: Depending on your organization’s policies, you can enforce restrictions related to iCloud usage on the device, such as disabling iCloud Drive, iCloud Keychain, or iCloud Backup. However, these are device-level controls, not direct access to iCloud accounts.
What Jamf Cannot Do:
• iCloud Account Access: You do not have access to personal iCloud data (like photos, documents, backups) stored in the user’s iCloud account.
• Personal Data: Jamf does not give you control over or visibility into the user’s personal data in iCloud, such as iCloud Drive files, photos, or personal emails.
If needed, you can restrict certain iCloud functionalities on managed devices, but you can’t view or manipulate a user’s personal iCloud account contents directly.”
Again, just because IT admins have access to and control over
some data on a business owned computer (we can in Jamf for example see what apps are installed on a computer) it doesn't mean
everything is accessible by the IT admins.