Good question. Even with Argentina playing for Messi (Although, at the level he's playing, maybe he's the one playing for Argentina. Anyway...), him being an alien, and, in theory, their next opponents being more favorable for goals (Switzerland–Norway/England), Mbappé scored three goals in the last World Cup final, without Olise and Dembélé on the wings...
With that said, not to sit on the fence, I'll go with Haaland!