The eco-system has changed dramatically and requires a new thinking and with that introducing new technology, policies and procedures. This, to enable such devices to be used in a work context and at the same time ensure that corporate devices, the data and apps are controlled and managed to prevent data from leaking or to be able to track devices if they are lost. In case of BYOD to ensure that corporate data can safely be wiped once a member of staff leaves the company.
In short: modern endpoint management.