It also shows how much the train networks focus on domestic travel. In nearly all bigger countries it is possible to reach most bigger cities within the 5h. But journeys in this time-frame seldomly go much beyond the border. There is still much optimization potential for transnational travel in Europe's train network.
It also shows an effect that the focus on high speed rail brings: rural areas are often very badly connected. Here in France they've even kept shutting down regional lines. That creates the train equivalent of "fly-over states": areas that you see from the train while going through, but that it would be impractical to go to.