Dimples or thread or sand or trim tape. It's all the same. It's there to stir up the air close to the surface and produce a turbulent boundry layer that is thin and hugs the surface. The laminar flow above will tend to stick better to this turbulent layer than it does to a perfectly smooth surface. Keeping the laminar flow stuck down longer and at higher lift coefficients produces a delayed stall and generally better performance at near stall conditions because the air tends to follow the shape longer. You pay for this with a touch high drag at the very low lift values where the air will tend to stay laminar anyway.

On the golf ball they use dimples because little bumps would soon get pounded away. It's not better to use dimples, it's just different.