Qualifying for the best of 16 doesn't make anyone better than others. It's based on 3 games.
A lot can happen in 3 games and better teams can lose to worse teams or draw especially since the lesser teams often play with no interest to attack and just sit back and force the favorite who have the pressure to win to attack them.
Spain won 3 straight tournaments and dropped out before the knockouts. Anyone want to tell me now that the USA are better than them?
Portugal played hilariously bad for example, still they are clearly a better team than Ghana or the USA.
Same for Spain, Italy or even England.
You match them up in 100 games in a final game against teams like Nigeria, USA, Algeria and so on and you will see that they will probably win 50%, draw 30% and lose 20%.
Some of the big teams struggle internally with chemistry or crumble under the huge expectations.
These teams have far more talent than several of the qualified teams for the last 16.
Also I am not changing my rating for the USA team at all. Their win against Ghana was extremely lucky and not deserved at all - huge individual error by that Ghana kid to go ahead after 30 seconds, then scored one off a corner at the end but between the first minute and the last minute only Ghana attacked.
I suspect that most of the Cinderella teams will be taken care off now in the knockouts now.