I would say that map size never was “most important”, at least not to the players, they’ve been complaining about huge but empty maps for years (the poster child of this, AC Odyssey was released in 2018, six years ago). It was just something devs and publishers pushed to one up each other in some kind of “bigger = better” way.
How is gamer defined here? I don’t have access to the full report but apparently it mentions Candy Crush, so I wonder how the statistics would look like if you removed games like that.
Honestly, I don’t get how this game broke Ubisoft. It’s not bad, but it’s also no great. They tried to not make it a classic Ubisoft open world Star Wars themed Assassin’s Creed and they mostly succeded.