Dany Laferrière, working writer who lives in Miami
Jean-Luc Marion, retired professor
Andreï Makine, working writer
Christian Jambet, philosopher, IDK what he does to pay the bills but his last published work was an essay in 2016
It looks to me like 20% of the part of the list I examined is made up of working writers in France, i.e. one of five. So extrapolating out, we know somewhere in France there are 8 well-known people in this one group who make a living just on writing. I don't know that that means that it is hard to make a living as a writer, but it definitely isn't an argument that it isn't hard to any particular level to make a living as a writer.
Again: The argument is not that writers don't exist, it is that it is a real difficult (like astronomically difficult) field to break into and make a full-time living at. I don't know why that statement is provoking this incredible level of resistance -- maybe because he phrased it so provocatively, I guess, and ignored some plausible ways you can work as an academic and also do writing and the two can support one another, which okay, fair play -- but regardless of that if you didn't like that guy's fairly detailed metrics, and instead are holding up this as your argument, I think you need to try again.