In France. In nations like the US (outside the DC-to-Boston corridor anyway) without a well-designed and -maintained rail infastructure, 1-2 hour flights are routine and not really replaceable with other options. Infrastructure investment pays off for decades and decades, and Europe has done really well here.
> However, if you're already arriving or leaving on a long distance flight, the whole overhead of getting to/from/through the airport disappears
That's an infrastructure problem too, though! There's no reason rail service directly to and from airports can't be integrated with the system. It's true in many places already, though I know nothing about France.