You need group owners for the feature that allows users to request membership to the group.
I think it makes sense in the context that users need to request to become members and not decide they are experts on their own. I think you do something similar with the @support-explorers group, don’t you?
@patrickemin I reported a bug last year that could help you avoid being added as a member of the group. But you’d need to find a workflow so that you frequently check if there are new requests in the request tab of the group because you won’t receive the messages in that case.
But it’s possible to remove yourself from the group after enabling membership requests: