Currently, if you leave a group you own and do not leave anyone in a rank who can take over the group, the group becomes absolutely useless and it just stays there permanently. This creates a ton of abandoned groups laying around taking up names.
In my case, I created a group but I left it acidentally. When I tried to rejoin, I was roled to Supporter and no one else could take over the group, disallowing me to reclaim my assets.
I suggest we force owners to transfer group ownership to someone when they leave to ensure a smoother process. The other alternative is to let owners delete the group for robux back or just nothing. Group owners should be able to reclaim their groups even after they leave if anyone else can’t take it.
Hope to see more changes to the groups section of ROBLOX.
There is an existing feature request for this here. To address some of your concerns though:
Roblox allows users to claim non-private groups, but you have to have some form of Builders Club. Since you don’t, the option didn’t appear.
If a developer wanted to leave an old group they owned to free up group space, this would force them to transfer all of their private group assets to someone else. Deleting a group is also not great – both of these cause lasting permanent damage. The problem is that the name is taken, and not the group itself, so this will best be solved by a solution limited to the name alone. See the responses to the thread linked earlier for more details.