[faidit]

This is only good advice if your company has high profit margins or funding and an expectation of growth, or your manager is extremely kind and trusting, or there are signs your manager is about to be fired/reorged and consultants or higher ups are asking if you want to replace them. More established industries or stagnating companies with low profit margin and no VC backing do not have a lot of room at the top, there are "negative selection" processes for management, and trying to do your boss's job is likely to be seen as insubordination. In those organizations the managers keep their job not by excelling at it (typically they would have leveled out due to the Peter principle) but by actively culling threats, and have all kinds of dirty tricks they can use to get rid of you if you show too much initiative.