That's because in this method you can control the cooking of the rice easily as you are checking periodically and this method ensures perfectly separated long Basmati rice. A rice cooker could possibly get similar results but the starch content is higher as you're not draining the water out. Keep in mind this kind of separated, fluffy rice is most important when you are having guests over or creating a special rice dish (pulaos maybe) or wanting to keep the starch content as low as possible when you eat rice. Same for making rice in an Instant Pot.