Clarify the idea of groups and rooms
While in a minimalist approach to the Alexa app it may be fine, there is a big confusion that I have noticed across numerous friends and family members involving the idea that groups are basically how a user can group devices with an echo as a "room" idea. I think that either better guidance within the app should be included or a slightly modified system of organizing devices should be implemented. It seems that normal users do not realize that an alexa enabled device goes into a group with other devices to control them separately.
Catherine Fredericksen commented
It doesn't appear that device groups are intended to do what you describe. Per the device groups doc https://amazon.com/gp/help/customer/display.html?nodeId=201749250 they say it's only to turn on or off a groups of devices together.