Why smartthings hub with sensors(motion, door) use zdo bind?

I’m using smartthins hub with IRIS sensors (motion, tilt…), I found the hub send zdo bind req to the sensor, my question is why they use zdo bind req instead of ezmode-commisioning?

Tagging @tpmanley

@linghao_duan, in the SmartThings zigbee network we want all devices to report their attributes to the hub. These zigbee attributes become events which can trigger SmartApps that can then control devices of any sort, including but not limited to other zigbee devices. I think the find and bind parts of ez-mode is more useful for directly controlling zigbee devices from other zigbee devices without going through the central coordinator. For example, a motion sensor could send on/off commands directly to a bulb. However, if you do that then you can’t also use that motion sensor to trigger say a LAN connected Hue bulb or a Z-Wave outlet.