Anyway, unless it's decaf tea switching over won't help much. Most caffeinated tea (which is most tea) has as much or more caffeine than your average cup of coffee, so if you're looking to break the addiction it's not an improvement (vis a vis the caffeine, anyway).
Do you have a source for this on-hand? I've heard that statement bandied about a few times before, but never seen it backed up by anything more than hearsay. Mayo clinic also says that, on average (considering there is a great deal of difference in beans, roast, amount used, tea type etc.) a cup of Joe will contain significantly more caffeine than a similar amount of black tea.
I've found this paper:
https://www.researchgate.net/publication/277774615_Caffeine_Content_in_Beverages_Commonly_Consumed_in_Jordanwhich is, as can be seen, comparing branded caffeinated drinks on a specific market (Jordan).
No matter how one reads this, teas are close to 10 mg/100 ml, whereas coffees range from a little over 10 to almost 150* mg/100 ml, where most 'regular' coffees have at least four times as much caffeine as black teas.
But the study shows large dependence on what type and brand of coffee we're talking about.
This chart, with admittedly rather poor sourcing (no specific studies):
https://www.math.utah.edu/~yplee/fun/caffeine.htmlplaces coffee at around 70% of strongest tea available on the US market, in caffeine content.
*that's why real caffeinators drink only espresso
So, I'd say the claim that coffee has as much caffeine as a similar-volume serving of tea is defensible only when comparing the strongest teas with the weakest (not-decaf) coffees.