I discovered whole leaf teas about a decade ago and was drinking quite regularly until recently.
I tend to like the 1st flush Darjeelings, Dian Hong, Tie Guan Yin, Bai Mu Dan, and anything naturally floral or fruity. The greens I take unsweetened occasionally when I feel I must moderate, but oolongs and blacks I sweeten big time --say 6 teaspoons of honey per the 16 oz I drink per day. (BTW, talking of floral, be sure to try a white Darjeeling, yes white.)
And that's what I think is overlooked here: the sugar. They're recommending your average 150-lb person consume no more than 9 teaspoons added sugar per day, so I'm getting over 2/3 of my sugar from one cup. So that's one health concern.
Another is the extra psychoactive compounds in tea, other than caffeine. Yes, I get an energy boost from the caffeine and sugar, but unlike coffee, I get this wonderful centered high and mental clarity. I just want to love everyone. Then, like any drug addict will tell you, you keep on taking just to maintain normal. A price I pay is constipation. I tend to overeat at this point as well. When I stop drinking, I come down: I feel listless, indifferent, unmotivated and otherwise mentally dead for about three days.
So really, as much as I love tea, I'm much more even-keel (and regular) without it. I mentioned this to a cousin (who was much more familiar with my kin going way back) and she said "Tea? Oh, we drink that only when we're sick." So maybe there's a genetic element in play as well. (I'm of Czech ancestry.) Still, I can't help but indulge once every week or so.
Tea also inhibits your absorption of iron. You won't hear about this unless you search for it. All the more reason to eat a lot more chocolate.