If it were up to unions, then there wouldn't be an advanced notice of strikes. That of course would create chaos. Imagine French ATC not turning up one morning. Sudden airspace closures would create chaos in France and beyond.

The current SNCF strike is however quite interesting. Their strategy of striking 2 out of 5 days means that they'll get 3/5 of their pay, the strike is protracted (stretched over two months rather than ~3 weeks of constant strike), and it's much more annoying for their passengers.

The reason why this doesn't get as much coverage has probably to do with the fact that there's always some kind of strike going on in France.