With zigbee you can “bind” devices together, so that their interactions work without needing the hub to intervene. I bound my IKEA buttons to my IKEA lights with my homeassistant controller (with some difficulty) so that even when the controller is offline the buttons will still work.
I think it's called 'direct binding.' All of my lights are directly bound to my switches, so they work even without the server or Zigbee coordinator running. With some switches, you can even bind light scenes directly to the buttons. For example, you can bind the four buttons of a Philips Hue Tap Dial to different light scenes using Zigbee2MQTT.
Some switches don't allow direct binding, though. All of the Hue switches I tried support it, but some Tuya switches don't. On the other hand, all lights from different manufacturers which I tried were able to bind directly.
The first year I had to fiddle a lot with the tooling. The uptime of HA/zigbee2mqtt wasn't great. It was good to have this as a fall back.
Do you have to choose between direct binding -or- controlling them through HA, or can you still control them through HA even when they are directly bound? Because I directly paired a switch with a light before (in Philips Hue), but then wasn't able to control it through the app anymore. Since switching to HA and Zigbee2mqtt, I just used triggers with switches, but wasn't aware that direct binding is a possibility. Gonna have to look into that now :)
I configure bindings through Zigbee2MQTT. You can view the bindings in the switch configuration, where you can also update or remove them.
I use Zigbee2MQTT to handle low-level Zigbee tasks such as pairing, binding, creating groups, setting up scenes, and configuring devices. Most of these things are stored within the devices and work without the coordinator/ha-server.
The configurations you set up in Zigbee2MQTT are synced with HA and can be used there as well. I use the options provided by HA for higher-level tasks, such as automations, custom sensors, statistics, and more. Everything I configure there will not work when the server/coordinator goes down.
Thank you, I did not realize that was possible as I had not found zigbee/z-wave products that advertised such functionality, at least when I was building out my system...which admittedly was several years ago now. Sounds potentially still more painful than the Lutron pairing process, but very good to know it's possible.