"I have no doubt about the value of Ligue 1. There are a lot of quality teams," Fonseca said.
"Ligue 1 is a quality league, one of the best in Europe right now," he added, ahead of his fifth-placed team's date with struggling Le Havre on Sunday.
Like Lyon in years past, Ligue 1 is currently dominated by Qatari-backed Paris Saint-Germain, who are aiming for their fifth successive title this season.
The last team to break their dominance was Lille in the 2020-2021 season.
One of PSG's former stars, Kylian Mbappe, famously took a swipe at those who questioned the level of Ligue 1 back in 2020 after Lyon knocked Manchester City out of the Champions League.
In a message laced with sarcasm, Mbappe posted on social media "Farmers League", followed by a clown face emoji.
Mbappe moved to Real Madrid in 2024.