Oh, I can't stand riding without a mirror! I surely didn't advise the OP not to use a mirror!

A mirror doesn't do anything about a rider's need to be able to look around.

To clear your blind spot (I wouldn't pilot a motor vehicle without mirrors AND turning my head to clear my blind spot before any maneuver, would you?? please say you do, that's how cyclists and motorcyclists get taken out all the time, by people not clearing their blind spots to merge) ... to look to the side to see what cross traffic is going to do ... to look at your rear tire if you've run something over ... etc., etc., etc.