I generally don't rate races based on the startlist quality. But I gotta say that the lack of strong teams often triggered defensive racing in the first two weeks, especially in some hilly/medium mountain stages.
The Stelvio stage was one for the ages and the battle between the emerging talents was very entertaining in the end. Still, I believe the riders didn't make a particularly good use of whay I think was a spectacular route.
The good: top Ganna, Etna, Stelvio, Almeida, Sagan stage.
The bad: lack of action in hilly stages, no real fight in the sprints, riders leaving due to COVID.
The ugly: Madonna di Campiglio, the Morbegno fiasco, Nibali never attacking.
Overall I'm unsure if a 6 or a 7. Using
@Netserk approach probably a 6 (2011, 2015, 2016 and 2018 better).