Well, Argentina was not a good team in the WC, but it was not the worst. We only lost to France and Croatia. France is a WC finalist and Croatia could be the other one.
Hektor
Croatia match: Rebic was on a Yellow and should probably have received a second YC before he scored the Caballero gift. From that point on it went downhill for ARG.
France: Which other team has scored 3 goals against France?
A WC contender needs a world class GK and a good defense. ARG did not have either
South America could have fielded a WC contender by combining Uruguay and Argentina teams.
Brazil was good enough but FIFA referees clearly did not like Neymar diving and simulating. With a well behaved Neymar, Casemiro playing, and more luck with finishing (Paulinho, Coutinho, ..) they should have beaten Belgium.
Point about media talk regarding 'European dominance': France looks like best team because of African born players. Future of football may belong to faster and more athletic players, like in basketball.
Maybe something to think about when planning Barça's recruitment of new players: can small and quick technical players still be competitive 5-10 years from now?