What one might mistake for sweetness (and it, of course, has a degree of sweetness), to me, is the roundness in mouthfeel from the sugars. The vermouth and amaro provide more than enough bitterness to cleave that contrast. The lemon garnish is essential.
Interesting, that is true. And the bitterness comes right up to the edge. The cocktail is acceptably dry, but it's not one that I would request. So next time, I might bring the Cynar down to about half, and increase the vermouth.