Griezmann didn't have much choice because even though he probably did even better than Mbappe at the World Cup, but he is more of the past and Mbappe is obviously the future. Therefore, if he had aggravated the conflict, then it would have been decided not in his favor, therefore, the reconciliation of the players in this situation is simply logic and not someone's specific merit. But in general Deschamps is giving a result and France are top 1 favorites to win Euro24, let's see how they can realize their chances.
Griezmann was either going to accept it or retire from the French national team, he does not want to retire yet so he had to accept the decision even though he didn't agree with it and neither did i, Mbappe shouldn't be the captain, even though he is the best player in the team, there are other senior players that deserve to be captain ahead of Mbappe, but the decision is already made and cannot be changed. France are surely the favorites for any tournament they are in right now, and they are favorites for the Euro next year and will probably win it, but anything can happen though.
It looks like Griezmann will still accept that decision and play for the French national team because he is unlikely to retire from France because he is one of the best players in the French national team.
I'm sure Griezmann is a bit disappointed by the decision, but he can only accept it because he can't do more to consider a decision that's already valid.
Mbappe may not be the only best player in the French team but Mbappe has managed to give France a lot of wins and he has shown that his game form is so good that he deserves to be the captain of the French team.
Moreover, Mbappe also successfully led France to win the 2018 World Cup and won the title of best young player in the 2018 World Cup.
Even today, Mbappe is still one of the best players in the world, so it is only natural that he was chosen to captain France.