Your options are not good. Keep in mind they are comparing joining AD, a 20+ year old workflow with modern MDM enrollment workflows. To say that the security surrounding enrolling devices has improved just a wee bit in the past two decades is an understatement. Microsoft also has AD viewed as a point of authority that can register a device with Intune, Apple does not have this same concept.
If your devices are all in Apple Business Manager, assigning them to Jamf may cause the enrollment process to automatically trigger with DDM. However, you would be accepting whatever situation those devices are in as "trusted" when enrolling which exposes your environment to risk. I have never needed to test this kind of post activation DDM based enrollment, so I can't say for sure how well it works.
Apple retired the ability to enroll into MDM from CLI back with macOS 10.15, which in turn ended the ability to use a quick-add package to enroll into MDM. This closed off any options to use something like CloudStrike or Axonius to deploy a package to attempt to force an enrollment.
The two main ways to enroll a device.
- Device Enrollment, where a user manually enrolls the device into MDM. This does not give supervision over the device but does give management. If the device is in ABM, you can use the profiles binary to change the enrollment type and supervise the device. This is an incredibly hands on enrollment method.
- Automated Device Enrollment, this requires the device to be in ABM, and have macOS reinstalled. On macOS activation the device is forced into management.
https://it-training.apple.com/tutorials/apt-deployment/#understanding-device-and-user-enrollment
As best I know, enrolling a Mac into Jamf really can't be automated. Am I wrong about that?
Technically no, device enrollment can be fully automated. Fully automated how apple wants it done, which is during device activation. Any enrollment of a fully activated macOS will require interaction, which is by direct design by Apple.
One thing I learned with managing Apple products. You do it Apples way or not at all, you cannot manage a Mac like a PC.
TL;DR: Apple has deliberately designed macOS device enrollment to require user interaction unless using Automated Device Enrollment (ADE) via Apple Business Manager (ABM) during activation. While technically possible to automate ADE post-activation, this introduces security risks. Fully activated macOS devices will always require some user interaction for enrollment, as per Apple's strict design.