Climate change is real and contributes to this but there have been massive fires in this region for over a century - primarily from the artificially planted Maritime Pine forests. The 1940s were particularly bad. Look up the Great Fire of 1949.
This isn’t a “it’s summer, and fires burn” type of a deal. Even though most fires are set by idiots on purpose, it spreads so well because everywhere is dry. Most parcs and fields look like savannas instead of the usual green.
Climate is changing drastically, exactly as predicted.
But that's not really the point being debated. Nobody is claiming climate change invented wildfires. But it is making the conditions for extreme fires more common. The IPCC concludes with high confidence that fire hazard conditions, including heatwaves and fire weather, have increased across Europe since 1980, particularly in southern and western Europe, even though ignition sources and land management still matter.
Climate change is increasing the odds that fires become larger and harder to control.
Western Europe has also experienced increasingly frequent and severe droughts in recent years. Those prolonged dry conditions leave forests and vegetation far more combustible, making fires spread faster and burn more intensely once they start.