1. Ramadan isn't just about not eating food. It is about abstaining from anger, lust, envy, impatience, greed for the sake of God.
2. If God had required people to fast for 5 days in a row, it would be very difficult for many people. God doesn't want to burden people, he wants to make things easier for them. God doesn't burden people just for the sake of it -- that would be a useless exercise.
3. When you are not eating and drinking, even if it is for 17 hours or so, you realise how much you really depend on it, and how much of a blessing it is. You feel more grateful to God for all that He has given you.
4. Ramadan is considered a blessed month because in it, the gates of hell are closed, the devils are chained up, and the doors of heaven are open. This makes it easier to do good deeds, so that when Ramadan is over, we can continue to exercise self-restraint and fear of God.