It is decoupled from home automation system.
It does just one thing, and it should do it well. No duplication of efforts by writting support for same devices in multiple softwares.
In future if I wanted to redo HA from scratch or swap it with some else software, I can continue using Zigbee2MQTT without repairing all devices.
Even, I can test different software in parallel, by connecting it to already running MQTT, to access sensor readings of my existing running Zigbee network.
I am running Aotect Zi-Stick (ZGA008), but I would probably go with Sonoff ZBDongle-E, which is based the same EFR32MG21 chip, but has external antenna.
I recommend to use #Zigbee2MQTT because it's decoupled from home automation software:
- ability to switch software in future without repairing all devices in different software,
- no duplication of efforts to add device support in multiple softwares,
- ability to run (or evaluate) different software in parallel against the same Zigbee network.