I think it's a feature to enforce network segregation and have gateways be intentionally chosen. IoT devices are known to be high-risk security. We should shape the solutions such that the minimal energy path is a good one.
If I have one building with one automation system but the building is too physically large or has walls that attenuate RF too much or where I don’t want a router node in the middle or where the latency across a mesh is too high, I want to be able to extend the network at low latency by plugging in another network-attached radio base station but without needing to manually pair each device to the closest base station.
If I have one building with one automation system but the building is too physically large or has walls that attenuate RF too much or where I don’t want a router node in the middle or where the latency across a mesh is too high, I want to be able to extend the network at low latency by plugging in another network-attached radio base station but without needing to manually pair each device to the closest base station.
Thread does this out of the box. Zigbee does not.