The main reason why your baby should be on a routine is so that when your baby cries you will know what the cry is for. When you follow a routine you will know what your baby needs next when it cries. This is good because if your baby suffers from colic, you will know when your baby is crying for a reason.
At the beginning following a routine could be much of a headache but it will pay off in the end because you will know what cry is for what and believe me they all sound different. If you happen to have an older child the needs you to travel them back and fourth for different reasons you need not to worry because your baby's routine can be scheduled around that time of the day. For example you can have the baby nap at this time while you drive.
My life was made a lot easier when I had my twins on a routine rather then letting them run the entire show. I had been able to make appointments around them and I could even do my shopping and errands with them not fussing at all. After I had my third baby people always said that it must be easier for me to have one baby rather then two but this was not the case and I had begun to wonder why. There was no routine that was in place, quickly I started to follow and my life was a whole lot simpler.
This is why a routine should be necessary for anybody that would like to have a somewhat stress free first few months. By following a routine your baby will have a feeling of security and they will also know what is going to happen next.