A cuff or turn-up at the end of a trouser leg on a man’s suit is there to protect the clothing from getting frayed and torn so easily. Indeed, the history of the trouser cuff reportedly dates to working men who used to roll up their trousers in order to avoid the mud and dirt from unpaved roads.
The extra weight also helps the fabric of the trouser leg to hang better, and if the trouser has pleats the added wright from cuffs tends to make the pleats stand out. This is the primary reason why tailors tend to hem trousers with cuffs if they come with pleats; but these days flat front trousers can look equally well with cuffs – it’s a matter of personal taste.
When worn properly, trouser cuffs are an indicator of refined style. The style does have a conservative reputation, however, and most trousers these days are tailored without turn-ups in order to preserve the line of the suit.
Trousers without cuffs can affect the appearance of height, however. The horizontal line of the cuff around the ankle disrupts the long vertical line of the leg and draws the eye downwards. This can make a man be perceived as slightly shorter. If you feel you absolutely need all the height you can get, no cuffs is the best option.