I think it’s fair to say that it’s only voluntary if it’s put in place by some consensus (and can be taken away by consensus). Say you work at a coop and all of the leadership is elected and can be easily recalled, then it’s voluntary. Even if you like your boss and don’t want their responsibilities, you ultimately don’t get a choice in the matter.
Someone else in this thread pointed out that this would just encourage bad actors to make sock puppet accounts to get around being blocked.