Beyond this, there are so many other health benefits to reasonable coffee/tea drinking. It's one of the few addictions that probably ends up being good for you.
I thought that for a long time, until I realized that afternoon caffeine was correlated with my inability to fall asleep at night. Cutting coffee (even dark chocolate) after lunch has greatly improved my sleep quality. Still love it in the mornings though.
That sounds like it wasn't obvious to you from the start.
You see me flabbergasted. How is that even possible?
First was an underestimation of the half life of caffeine. It stays in your system for a while, and stacks when you have multiple throughout the day.
Another was my personal sensitivity to caffeine with regards to sleep. I know many people who can't drink coffee at all and others who can drink it as a digestif. I'm somewhere in the middle.
The last is being embedded in a coffee-drinking culture, without personal awareness of the above two points. So I would drink it later than I should with people who didn't (or didn't know they) have a problem drinking it at that time.
Then there are infusions of fruits, leaves, etc which are not strictly tea.
And there are the above teas with other plants or oils mixed in (e.g. jasmine flower, bergamotte, ...). As long as you don't add much sugar I doubt these have much different impact unless these are plants with known effects of their own (ginseng, ginko, lemongrass, ...).
If this effect is being observed in both coffee and tea, my guesses would be it's either caffeine, something with the roasting, possibly fermentation (but I'm not sure if all tea is fermented), something with fluid consumption, or something with the mental ritual of drinking mild stimulants.
[0] https://brandongaille.com/20-uk-tea-industry-statistics-and-...
Which parts of the world prefer green? Chinese and some Asian restaurants here (Poland) feature green tea quite prominently, but that’s the limit of my experience.