To be fair, he has been excellent at every team has has played so far: Defensa y Justica, River Plate, Benfica and Argentina. Not only that, he has won on every single one of those teams (well, except with Benfica for obvious reasons). And, with the exception of River, non of the trophies he won were expected. He won the Copa Sudamericana and Recopa with Defensa (that's like winning the Europa League and then the European Supercup with a team like Bournemouth) and then the World Cup with Argentina after 36 years. Being a crucial player in all of those.
The kid is just special, but then again, not all World Class players work at every team. Di María and Pogba at United, Hazard and Bale at Madrid, Griezman at Barca. Heck, if Messi wasn't Messi and just a kid coming up, he would have been benched forever after his first season in Paris and everybody would be talking about how he was just all hype. There are so many different factors that come into play when trying to adapt to a new city/country and team.