I had recently read some claims that one of the reasons the ancients watered their wine was because of its high alcoholic content, compared with our (unfortified) wines today. This appears to be false. (My wife, who made wonderful, dry country wines, also said so. )
There has been mention on here before about Epicurus, as he was dying, drinking undiluted wine.
There may have been other reasons for watering wine, though, in addition to concerns of sobriety.
Wine throughout history: What were ancient wines really like?
www.wineinvestment.com
Was ancient wine more alcoholic than modern wine?
Because the ancient Greeks and Romans mixed their water with wine, it is often assumed that their wines were considerably more alcoholic than modern ones. Is…
www.badancient.com
Note: I do not water my wine; my wife sometimes does (and she imbibes infrequently).