I don't agree that stars in the Belgium team are too old. De Bruyne is 31, Curtois is 30, Lukaku 29... All of them are around 30 years of age and that is the time when a football player should still play at their best. Especially for the star players like the ones I mentioned. OK, Mertens is a bit old with 35 but he is one of rare players that old in the team.
Belgium has a golden generation but they did not achieve anything from them. This World Cup and Euro 2024 might be last big tournaments for this golden generation. If Belgium can not win this World Cup or the next Euro, they will likely see the end of this generation without any big title.
It is a bit odd to see a very terrible performance of Hazard after his transfer from Chelsea to Real Madrid. He is about 20% of this best in Chelsea a few years ago. Belgium now is more relying on De Bruyne but Hazard is no longer important for them.