Belgium was rumored to be able to win a trophy some time ago at the previous World Cup as well as the European Cup but that didn't happen, and this will be the last chance for the best Belgian generation as far as it has ever existed, to qualify for the group phase they can but to the quarter-finals or semifinals it's still not clear because they will face teams that are just as good later.
I am not very enthusiastic about Belgium this time. From what I have seen over the years, teams that are dependent on a single player (not just talking about Belgium, but also about teams such as Portugal, Norway and North Macedonia) almost never performs well during global tournaments such as World Cup and Euro Cup. Now some may argue that the case with Argentina is similar. But IMO, that is not the case. For Argentina, apart from Messi, they have very good players such as Ángel Di María, Lautaro Martínez and Paulo Dybala.
Many always consider Belgium to be a dark horse, but this country never lives up to expectations and only once were they able to finish third at the last World Cup. By the way, it's not a one player team. I take it you are talking about Romelo Lukaku or Kevin de Bruyne. Apart from those players, they have one of the best goalkeepers in the world Thibaut Courtois, midfielder Axel Witsel, strikers Dries Mertens or Eden Hazard. With players like that, they should be successful because it's likely that at the next World Cup, a lot of players will leave the national team.