@randx checking if I understand what you suggest:

- make a helper for `- unless member.owner && group.last_owner?(member)`, put it under `application_helper` and use it in the groups and profiles views to hide the button in that case.

    I feel this brings ability logic into views. I could move `can_be_removed_by` logic into the `Ability` model as an alternative, and use it in the views.

- point the remove user button on the group view to the profile leave URL in case it is the current user being removed. Remove the `except` authentication from the group controller.