How to deal with imported rooms?

I’m testing HA only since some days, maybe that’s why this is a stupid question. However I have installed the integration of HomeMatic Ip Cloud. After that I found all the “devices” which are available in the HomeMatic IP app. In that app all devices are added to rooms. When I add the devices in HA, also these rooms are added as devices. Now I have to add these room-devices in HA to the HA rooms.

From my point of view, this doesn’t make sense. But what should I do with those imported room-devices? Deleting seems not to be possible. I can deactivate them, but in this case they appear every time as new and not added devices.

Do I need them and if so, for what thing? If I don’t need them, how can I completely remove them, so that they don’t get in the way?