In some scenarios, it's desirable to have keep two entities in sync. In my case, the most common scenario is when I have a smart bulb on a circuit controlled by a smart switch. The smart switch is set in 'smart bulb' mode, which means it sends events for on and off and maintains state, but does not actually cut the power to the light bulb. This is important because while it's useful to have a physical switch for a smart bulb, smart bulbs are not designed to be unplugged. When a smart bulb is unplugged, it can have undesirable effects, such as impacting the Zigbee mesh if the bulb is Zigbee.