Interesting! I'm running a three monitor setup and have the taskbar only on my most right display in the right side of the display, that way I have two entire displays entirely free for use and on the third display I think having the taskbar in the side takes up less space. (My displays are 16:9, 1080p each)

To me having the same thing on every display feels redundant. But that's probably just me, because my brother has the same setup as what you described.