Yes, Croatia played very strangely, very strangely. I would not say that they played attacking soccer, rather tried not to play total defense, knowing that anyway Argentina will score, which in general is what happened, but I expected that at least one goal Croatia will score, after all a team strong, experienced enough, but the result was 3-0 in favor of Argentina. I think that the second goal, which the Argentines scored somehow very easily, "undermined" Croats and after the second goal, they themselves did not believe that they could beat Argentina.
And when Argentinians scored the third goal, they had already relaxed and probably kept the upcoming final in their minds, played not roughly, did not foul, which is not very similar to them.
Croatia lost because they fell into the trap of Argentina, simply explanation.
Argentina are stronger than Croatia but they sacrificed ball possession for Croatia and waited for combination of Messi with his great vision and accurate key passes and the speed of Julian Alvarez. We witnessed how they succeeded with this approach as three goals for Argentina come from almost a same way.
Lovren and Gvardiol had a worse combination than they used to have but if Argentina did not have Messi and Julian Alvarez, they would have not break down defense of Croatia.
The first penalty opened the match knot for Argentina and it becomes more easily later for Argentina to play. The second goal simply made a win for Argentina looks more clearly.