Multi component devices like 2 gang switches:
Power strips:
Or dual relays:
Having a DTH with A parent/child construction allows the user to give each child a custom name and allows you to then voice control them from Alexa.
Multi component Edge drivers don’t at present allow the user to change the name. Even worse for many users is that only the equivalent of the parent is exposed to Alexa. You can’t control the child components by voice at all. 
@nayelyz is aware of the issue, but no timeline has been given for fixing it, and it is limiting the usefulness of edge drivers for a number of people.
Existing discussion thread:
[ST Edge] Issues with multi-component devices and third-party integrations