Ansible is primarily a "push" model, which is hard with systems which may or may not be online from various locations (eg laptops).
Plus having a cross platform MDM would allow an IT team to manage a fleet of end user devices without having to become experts in each of them. For example, the MDM could have push button "erase this machine", etc
Very good point on the push model when it comes to devices like laptops.
Not sure how I feel on the second point. Managing Linux at scale, aside from the laptop point is pretty easy. Maybe companies need better help desk employees.
Plus having a cross platform MDM would allow an IT team to manage a fleet of end user devices without having to become experts in each of them. For example, the MDM could have push button "erase this machine", etc