Earlier quoted context omitted.
Sugar (in large amounts) isn't so great for you either ... And caffeine from coffee/tea while fine in moderation, becomes really bad if abused as part of a pattern of chronic sleep deprivation which is really common.
There is neither sugar nor caffeine in herbal tea - you cannot drink too much of it I have probably had a sum total of 10 mocktails in my life - each of which has less caffeine and sugar than a half can of coca-cola
I was just being a pedantic jerk reacting to: "no downsides."
There are often possible downsides to anything one can do ... but that doesn't mean it isn't something worth doing. I love to hike - I could break my ankle or fall of cliff - but that doesn't mean I should never hike.