I've never understood why some workers adopt this mentality. In my previous job at Domino's as a delivery driver there was another driver there who had been working there for about 7 years and was constantly giving orders and “suggestions” as if he was a manager but he wasn't because drivers can't be managers. He also was being paid the exact same as me (minimum wage) despite giving himself all this extra responsibility.
There was also a similar situation with one of the in-store staff members. Despite being paid the same as all her colleagues, she was constantly trying to micro manage people and push the companies targets – as if she was going to see a penny of the increased profits!
I understand some people want to move up the old corporate ladder but these people had been working there for years and have never applied for a management role and one of them literally couldn't. So what's the point in giving yourself extra duties and responsibilities without extra compensation?