I also have another question.... how do you imagine that Argentina, current champions, will perform in the next World Cup without Lionel Messi and Ángel di María?
I think Argentina need to be concerned early on about how they are going to deal with this deficit in their attacking team.
Argentina has excellent young players that can continue from where this team left off. Alvarez, Lo Celso, Romerio, E. Fenandez, Nico Gonzalez, Taglafico, Molina, Montiel, R. De Paul, Lisandro Martinez, Ganacho, Mac Allister are all young players that are very good. They don't need to have a player as good as Messi or Di Maria to win, they only need to play as a team, the same way they played in the Copa America and World cup. For now, Messi is still around and he'll still continue to help them but I doubt he'll be available for the world cup in 2026. I don't know if they have a good goalkeeper like Martinez though but they have less than four years to find one because Martinez won't be what he is today by 2026.
When any team belongs to remarkable player, different kind of motivation works within the team which can motivate even the weaker players to great deeds. Messi's role in the Argentine team is similar. When Messi is in the team, it is not impossible to expect good things from the other players because of the spiritual stimulation. It remains to be seen how the mentioned players play in the upcoming World Cup. The extent of Messi's contribution to the team will also be quantifiable.