I agree with the argument that most of the players will be in their late 20s or 30s. But in the previous editions, most of the European teams had good players in their early 20s. However this time (Qatar 2022) only a few of the European teams had such players. Some of the teams do have players who are 20 or 21 years old, but they are no match for the more experienced players. Players of the calibre of Erling Håland or Ronaldo of 2006 are extremely rare nowadays. Let's take the example of Germany. They have a few - Karim Adeyemi, Youssoufa Moukoko and Lukas Nmecha. But these players are not even regulars in the playing XI. Most of the attack is being done by Müller, Gnabry and Gündoğan.
That's why all teams have coaches who decide if experienced players should play or younger players. But when you look at the game against Japan that Germany lost, their worst players were Musiala who is 19 years old and Havertz who is 23 (I still count him as a young player). Maybe they would have won the game if their coach put more experienced players into the game from the start. Who knows. But every coach must think about introducing young players and that's best done by combining few young players with experienced players. If they keep playing with experienced players, the time will come when those players won't be competitive anymore and those younger players won't have experience in playing important games.
I think experienced players or young players argument doesn't matter and only better player should play. Doesn't matter how old a player is, if they are the best option for that position then they are the best option for that position, there is nothing else about it.
You could be 18 years old, you could be 38 years old and if you are the player that your nation should play because you are the best, then they should put you in there. Old or young shouldn't have mattered and sometimes it unfortunately did, like in Germany case. I am sure that most managers don't do that though, they probably pick the best players and do not consider age to be an issue at all.
That's right, the best players should always play, regardless of age.
Who can say that Messi, Benzema and Modric are too old and should stop playing.
Real regularly wins the Champions League with such old players, and the Croatian football team won two medals at the last 2 world championships with Modric as the main player.
I sincerely hope that Modrić will finish his football career at EURO 2026, and to win any title in football, the experience and mental strength of the team is always important in addition to the individual quality of the football players.
It's difficult for me to say why Germany lost to Japan, but I think the reason is not only weak defense but also ineffectiveness in attack and it is obvious that this team needs some changes and new players in the team.