Why is a tiny cell more efficient than a large cell?

Small cells are much more efficient. If there were large cells that we did not need a microscope to see, materials would take too long to travel to the center of the cell through the cytoplasm. But that is coming from the stand-point that the materials stayed the same size. If the materials got bigger as well, then there would be no problem but in real life, the particles would stay the same size and the over sized cell would die.