Tea is healthier to drink than water, due to the flavonoids in tea:
These polyphenol antioxidants are found in many foods and plants, including tea leaves, and have been shown to help prevent cell damage. …
Other health benefits seen included protection against tooth plaque and potentially tooth decay, plus bone strengthening.
This from a new UK study. Furthermore, even though tea is caffeinated, its net effect still produces hydration. So it replaces fluids and has antioxidants.
I think I’ll go have another cup!