While I am one of Messi's biggest fans in South American team, I believe the current team will need luck to win the world cup. The last time a South American team won the FIFA World Cup was Brazil. As a result, Argentina's chances are stacked against them. It doesn't matter what, European countries always dominate. Yes, it would be incredible to see Messi or Ronaldo lift the FIFA World Cup trophy in 2022.
I doubt Portugal will reach the final, although I would like to see it. Portugal has the players to get there, it remains to be seen if they will be focused enough for that.
But it would be very nice to see an Argentina vs Portugal final, because they are two teams that have never played against each other.
I wouldn't underestimate them. They are much more flexible and versatile than they used to be in the past. The offense is pretty strong in my opinion. If they are all available and fit I don't see a reason why they shouldn't be able to compete for the top 5 as well. I think when it comes to the semifinals and final, it is rarely the case that one team totally dominates the game. It is the little things that then decide it. On a good day we all know that Ronaldo can still score some crazy goals. Could become his tournament so to say.