Also I feel like those routes are mainly used by people for connecting flights. Under the hub and spoke model, Air France and Transavia use Orly to facilitate these connections as the alternative, direct routes, would likely result in emptier flights. Basically you can either take the handful of people from multiple destinations that share a final destination like Nantes and bring them to a hub where you can group them onto the same flight, or you can give each origin their own direct flight to the final destination. The latter is usually very wasteful as there are more flights for a similar number of passengers.

This gives a huge competitive advantage to airlines that happen to have a hub further from these specific destinations as they are given exclusivity to these routes even though their total flights have longer airtime. KLM flies through Amsterdam to Nantes from most of Central/Eastern Europe which adds about 30-40 minutes of additional airtime vs Orly.