There's different types of tea and they're all healthier than coffee. Coffee is nasty unless you add a lot of sugar or creamer while tea is naturally good and benefits the body with its antioxidants. Coffee is just loaded with caffeine and does more harm than good.
In the 1920's, there was a grain based coffee substitute called Postum, which was marketed under many taglines, including "Lose Eyesight Through Coffee Drinking." Now, please keep in mind that these are the folks that thought smoking was good for you, and if even they knew that coffee is terrible for your health, then there must be something seriously wrong with it. We have yet to see the day when a substitute for tea is developed due to fear of harm to the health of anyone at all.