Well from my observation of everything, I think the Brazil team is just not loaded with the superstars they use to have and moreover the squad is now filled with supposed stars and the worse part is they don't play together that samba football anymore, it's all individual nonsense everyone claiming to be the best just not like the good old days when you have the likes of rivaldo, robinho, Ronaldinho, kaka, and so many football great in a team and still play very well.
I have posted about this before. The problem with Brazil is that they have remained where they were three decades ago, while the other teams (especially France, England and Argentina) have made rapid progress. And one important thing we should remember here is that the domestic league in Brazil is not very competitive. Most of their players migrate to European countries to play club football, and this in turn impacts the team bonding and cohesion when they return to represent the national team.
Brazil does not look well developed lately, and I also see that their domestic league is not very competitive, and seems to be declining, their regeneration is not as good as it used to be, even now it looks more on the way of decline, whereas in the past Brazil was one of the warehouses of very good players in the world, the strongest contender we can mention, but unfortunately for the upcoming world cup Brazil is in doubt.
Argentina, England and France do look much better, and I think if you look deeper they have moments for their players to be much more developed, their domestic leagues are also running quite very well and competitive, only Argentina I don't monitor.
Most likely if England has a much better coach and the players have good cooperation with the resources they have today I think England can find the 2026 world cup champion, but we don't know why there is a little doubt in this England when they I think have quite excellent resources that can be used to dominate.