However, the 23-year-old noted a distinct difference in the level of professionalism and infrastructure between the two French squads.
"It is a logical and normal evolution in a career. Here I really realize that I have arrived to a real World Tour team and that feels good, you feel that there are resources and it is really pleasant to feel that to progress even more."
While he is enjoying the "resources" of Groupama-FDJ, Costiou remains grateful for his start. "I am very happy to have spent my three years at Arkéa, they were the ones who opened the doors to the professional world for me and the first to trust me," Costiou reflected. "But I needed a change and the
Groupama - FDJ project suited me very well. It is what I was looking for, a team that trusted me and here I think I have found it."
He still maintains close ties with some of his former teammates, including
Kevin Vauquelin, who was also forced to find a new home in the peloton, in his case at Ineos. "Kevin has been a buddy for a long time, and before coming here I rode with him, so he is really a mate, we get along great," Costiou said. "Inevitably we tell each other how it is going in each distinct team and it is nice to have the other's feeling too."
Costiou also revealed some of the races he will target this upcoming season. "It will likely be more or less the same races [compared to 2025], it will be a restart in France, the Grand Prix La Marseillaise, the Étoile de Bessèges, which I have never done actually," he outlined. "And after that it will be a program like
Paris-Nice and the Ardennes and then after normally the Dauphiné and maybe the Tour de France, but that is still to be redefined."
His primary goal, however, is to turn consistent placings into victories. He had many solid results last season but only one win. "I would really like to win several races a year, because for two years I was winning one a year, but I want more. Winning three or four races, that would be really great, no matter which ones."
He has already identified
Paris-Nice as a key opportunity to make his mark. "To shine in the World Tour too, that is really the goal, whether on a Tour de France, on a Paris-Nice or the Ardennes, that is really the goal. Paris-Nice is quite open this year, it is not a pure climber's course, there are things to do. If I could get a good result there, it would not be bad," he concluded.