The most recent update to Zigbee2MQTT has introduced the ability for Zigbee groups to be auto-discovered by Home Assistant using MQTT Discovery. This new addition applies to lights, switches, covers, and locks and will make an optimized self-hosted Zigbee setup much easier to achieve, especially for those wanting to avoid the configuration files.
Zigbee groups have long been supported by Zigbee2MQTT and are a great way of reducing Zigbee traffic and thus improving both its own and co-existing Wi-Fi networks performances. I have extensively written about why you should be using them in a previous article. However, there were still two hurdles many were not willing to overcome: Firstly, Zigbee groups had to be set up using YAML in Zigbee2MQTT's configuration file and secondly, the configured Zigbee groups weren't auto-discovered by Home Assistant. What that meant for the user is that Zigbee groups not only had to be created using YAML, but also had to be added to Home Assistant using a configuration file.
The first stumbling blocked was recently solved by the addition of an official web dashboard for Zigbee2MQTT. Using it, Zigbee groups can be created at ease. The second issue was addressed in a feature added in Zigbee2MQTT V1.20.0. With this release, Zigbee groups will automatically be discovered by Home Assistant, as is already the case for devices.