Brazil and Argentina will very easily qualify for the world cup. because the contestants in the CONMEBOL zone are only 10 participants. and 5 of them will qualify. and a fairly balanced opponent for Argentina and Brazil is only Uruguay. in terms of squad material Uruguay can be competitive with Argentina and Brazil, the other quality is too far compared to Argentina or Brazil.
The rules changed after FIFA announced the 48 teams World Cup in 2026
Now the CONMEBOL qualifiers will have 6 teams qualifying directly and the 7th place team will try to classify in a play-off match (probably against a team from Oceania, and usually teams from South America win that the match and the spot)
So the chances are even greater, only 3 teams will be out of 2026 WC
I agree that there is probably little reason to be pessimistic for Brazil whether they will qualify for the World Cup 2026, but since they won just one game after six games have been played, I think it is at least time to be more serious about the situation they are in. There aren't really any easy games in the CONMEBOL qualification and look at the teams right behind them. That is Paraguay and Chile and of course Brazil is the favorite in these games, but Paraguay and Chile isn't like some tiny country from Europe. So there is still some room for error, but if they don't start winning their games, needless to say that they will get in trouble irrespective of being one of the biggest football nations in the world.