At the moment, light groups seem to need a little bit of TLC. In my opinion, they are a fundamental component for home automations, particularly when integrating with voice control, but they don’t get some of the enhanced functionality due to being an older feature.
Right now, configuration is through configuration.yaml, and as a result they do not generate unique IDs. I believe that if the functionality was expanded to a more modern integration, they could be assigned unique IDs, which would allow them to use the functionality available to entities with unique IDs.