It might be true the best team only has 28% chance of winning the World Cup. Though, we should know that it leaves only 72% chance for the rest of the 31 teams to win, and they are not uniform. So maybe 28% for the best team, 20% for the 2nd best, 12% for the 3rd best, etc., which sounds fair to me.

There are 32 teams playing the World Cup, if one of them is a 1:3.5 dog, they have a pretty DAMN GOOD chance. The betting odd is usually sth like 1:4 or 1:5, I think.

More importantly, the team which wins is the better team, by definition. It is a question whether they can perform consistently in a series of matches with the correct strategy each time, whether they can adapt to changes, whether they are focused at the important moments. Certainly there will be luck and drama, but the team which plays better (for most of the match duration) wins much more often than that number 28% tells you.

Look at professional poker. You can for sure say that there is more luck involved, but times and again the familiar faces show up at the final tables.