Most of us would happily settle for a longer trip just to avoid dealing with the airlines or having to stay awake and focused on a horizon for hours at a time.

Just note that that the strength of high speed train in a country like France is that it's totally competitive from a time point of view

If you want connect Paris to Marseilles (2nd biggest city), it's 1h25 flight or 3h02 by train. However, The train station is at a central location, while airport is out of town, let's say you need 30 minutes to reach the airport, and 30 minutes to reach the city from the airport. This alone ads 1h to trip, now you are at 2:25 versus 3h02. With train you don't need to clear security. If you show up at the train station 10 minutes before the trains leaves you have the time to grab a coffee, and reach the platform. With plane, you need at least 30 minute to clear security and reach the gate. Suddenly, you are at 2:55 versus 3:02.

OK but what if your final destination isn't the city centre ? Well, if you want to visit the airbus helicopter plant located on Marseilles Airport indeed you should better fly, but if you want to go to Aix-en-provence, well you're lucky the train also stops there...