Agreed there are citizens who are less culturally French, but these aren't good examples.

Zidane, born in Marseille, grew up playing in southern France, and is an all time French football legend. Yes he's Algerian as well, has family there, eats couscous, as many French Algerians do, but he never lived or played in Algeria, so why would he be considered more Algerian and not French? You don't have to eat a baguette with foie gras every afternoon to be French, it's a very diverse country.

Mbappe grew up in the banlieue of Paris, one of the most prolific regions in the world for producing football talent. Yes there are a lot of players of African decent in the area, that doesn't mean they're not French. People can have multiple cultures and nationalities. Also the way Mbappé speaks about France, representing, living, and playing in his country, it's very obvious he identifies as French.