@jon@jmovs@Sustainable2050 I don't understand how you get to that conclusion.
I don't know about the inland pricing of airlines vs trains in France, but here's a simple example: from Rotterdam to Marseille round trip end of May/early June is 404 eur by train. Amsterdam Marseille by plane is 212 eur. And only Air France KLM has that route.
Amsterdam Nice costs less, because there's are 3 airlines on that route.