Not a bad start, my first GI renders were pretty horrible lol. I agree with younglion, way too much geometry for something that simple, not a good habit to cultivate.

Why the scene doesn't look realistic.

As others have mentioned before, the edges are too sharp. The texture isn't believable, as a matter of fact I can't see a texture at all. As it is right now, it looks like one big piece of plastic and not pieces of wood joined together. Thats the thing with these modern/contemporary type bits of furniture is, they look real cool in realife because their beauty is in their simplicity unlike the antique pieces that tend to be more ornate and lavish, so we might underestimate the details that should go into these modern pieces/scenes for them to be believable.

I wouldn't go as far as to say you need a bump map in this case, but by looking at the ref I think you a slight reflection that is blurred. I don't think you need to have caustics turned on but you definitely need some shadows. if the lighting isn't good, it'll kill your image.