Lionel Messi is the most decisive player in the world. He's so decisive, that sometimes it seems as if he can do everything on his own. But the reality is that when he's at his best, when he's simmering the most, is when he has a team accompanying him and helping him. If his teammates build the roads, knock down the walls and offer him options to link up, it makes it easier for him to be decisive.
Once, against Paris Saint-Germain, he changed the game coming off the bench despite being injured, but the Rosario-born forward cannot produce miracles every day. Coach Ernesto Valverde got it wrong in Rome and opted to repeat a side that was tired and lacking freshness and ideas. You have to let geniuses get on with their word, but it's much better if you make it easy for them.