That is the way most international tournaments are run whether the sport is basketball, soccer, rugby, etc. How do you think basketball is run in the Olympics and world championships? They have a group stage round-robin followed by a knockout stage. Why is that so alien to you?
The NFL is divided into groups to decide who gets into the playoffs, just like MLB and the NBA. You play the regular season to determine who gets through to the playoffs and to set up the seedings.
You should review the various factors that decide who gets into the NFL playoffs. It is just as, if not more complicated as to who gets out of the group stage in the World Cup.
“Why is that so alien to you?”
Where did I say I enjoyed watching basketball at the Olympics? I don’t like a lot of their screwy tournament structures either.
And you are incorrectly conflating the NFL/NBA/MLB S-E-A-S-O-N with the World Cup F-I-N-A-L-S.
The World Cup already had its equivalent of a Season, with all its qualifiers, and that is over and done with. They’re in the ‘playoffs’ now...and the US made it to the 4th round by winning ONE game.