I don't like Mbappe, seems like another prick (maybe you need this to be a top player), but 4 Euro wins and he was right, Argentina win 1 and he is wrong. Funny that.
KO competitions aren't linear like that anyway, it's just that there are less odds of a SA winning it when they only realistically have two teams who have the talent, resources and population to win it (in a specific WC the likes of Uruguay, Chile or Colombia could go far, but statistically what I've said has been true since football became truly professional), whereas Europe have several, but Argentina and Brazil will always hold the SA end up because they are historically leading nations who develop lots of players, with Brazil still being pretty much #1 in most of those parameters.