Source (which I know you've already cited), but I've done the maths.
Since the Wikivoyage total is 'live' and the Wikitravel total is Feb, we'll have to make some assumptions, but I believe them to be valid.
Let's take the Wikitravel first. 13 years and 1 month, assuming the start of 2013. 2,541,627 over that time = 194,264ish edits a year.
Wikivoyage = 3,020,088, divided by 13 years and 6.5 months = 223,021ish edits a year.
So based on that, Wikivoyage wins.
However, this is kinda moot, as Wikitravel only launched, according to Wikipedia in 2004, and Wikivoyage in 2007. So the numbers seem a bit strange to me.
What I'd focus on instead is the Alexa rank, which while Wikitravel is ranked higher, Wikitravel has slipped from 3000th to 6000th in the past few years and continues to slip as people move to the wikivoyage. That's my feeling anyway, and while it's still more 'ranked' and familiar to people (friends often mention wikitravel, never wikivoyage) the editing community certainly seems to prefer wikivoyage.