I don't think they make you look sharp. They're a uniform, stick a suit on and you're just another person dressed in grey or black. It doesn't exactly do anything interesting with the eye.
Now, granted, there are various cuts of suit, and different pockets, ways of making them roll the shoulders to make you look broader or... but I don't really find that a well made suit is dramatically more interesting than a poorly made suit.
Perhaps to other people it is, and then I could understand better why people would choose to wear them if given a choice. But to myself a well made suit's not really more interesting than a grey T-shirt and has additional social connotations of being subservient to whoever's enforcing the dress code at the time.
> People who say we should do away with the suit are arguing to do away with centuries of evolution in professional men's attire.
What's the selection pressure supposed to be? Cutlery serves an obvious function. It's not clear what desirable function suits serve.