Really dependant on your needs and desires. For me it started with a desire to use the Xiaomi motion sensors and contact sensors I owned. Once I learned that they are just as stable on HA as they are on a Xiaomi gateway, I bought more at a really good price from another community member that wanted to get rid of them.
I later switched from ZHA to Z2M and the number of possible Zigbee devices and features of each that could be accessed expanded immensely. I started experimenting with adding other devices that had previously been problematic, difficult, or impossible to reliably connect directly with Hubitat, such as IKEA devices, Lutron Connected Bulb Remotes, and those prevously PITA Gen1 OSRAM Garden Spots, which now work perfectly with Z2M.
Everthing is brought back to HE for Automation via Home Assistant Device Bridge. I have a few automations on HA, but they exist primarily to get around stateless devices that don't create entities, so I instead automate button presses on HA with virtual switches on HE so I can use them in HE automations.
I also use integrations for my:
- Hyndai Ioniq 5 (Warm the car via Alexa, Lock the doors, ensure we have enough charge, check the EV battery via Pico button press at any of my Sinope themostats, and confirm the 12v battery level in the Apple Home app on our phones)
- Moen Flo (There's an HE integration which I also use, but there's one additional way I use it that just works better for me on HA)
- HomeKit Device (formerly HomeKit Controller) for my Aqara FP2
- Oral-B toothbrush (so I can confirm the kid really brushed his teeth properly)
- Philips Hue (gives instant feedback and supports access to motion sensors joined to the Hue Bridge)
- Sense Home Energy Monitor (supports emulated Kasa plugs so I can bring the readings of devices that already have energy monitoring, as well as the readings from my Aeon HEMs into Sense)
- Sonos (allows me to use my IKEA Symfonisk Sound Controller with Sonos, without the stability problems I had with that device on HE)
- Xiaomi Miot Auto (Brings my Qingping AQM Pro into HA, and thus HE and Homebridge too)
- Orbit B-Hyve (allows me to use my Misol soil moisture sensors to work with the Smart Watering feature of my B-Hyve hose valves)
- Insteon (Although I don't use this for integration to Hubitat, I do use it to adjust Insteon device specific options, and to add new Insteon devices without needing to subscribe to the now, pay-for-use Insteon app)
- MQTT (serves both the Z2M integration, and two D1 Mini EPS32 boards that are flashed to give direct local integration of multiple Switchbot devices with HA, and thus use them in HE automations)
