[londons_explore]

Businesses prefer something with ongoing support, and that tends to be a subscription service.

[happyopossum]

In the modern world, MDM also works far better as a cloud service than a privately run server behind a corporate firewall.

[phpisthebest]

Admittedly this may not be the case for apple devices, but I know more than a few enterprises that use Android MDM on Prem behind the Firewall specifically for Devices that should not ever contact the Internet, they are used for internal processes.