Apparently there is little current economic incentive (or regulatory push) to streamline the process and take on airlines in cross-border travel: Railway companies are national in nature and by history. The share of cross-border travelling is small; the income mainly comes from national rail. - Obviously if they streamlined the process to take on airlines their revenue would increase. But perhaps the cost of streamli…
Rail services in European countries are not covering their costs in any country, as far as I know. Speaking of Switzerland (which is notably at the extreme end in terms of costs) public rail services are run a lot like infrastructure projects / economic booster packages by the government. Whether or not ticket prices or capacities are increased is more down to politics and economic perception than actual demand. So i…
Also, the EU mandates open track access, which means technically it's possible for private companies to compete (and they do, there are several private operators like Flixtrain, RegioJet, LeoExpress, even a high speed one in Italy, Italo).
It's also possible to have rolling stock that is fairly usable all over Europe (RIC carriages, usually 200km/h). There is even a bit of a market for used vehicles. As for locomotives, traditionally they only work in one country, or perhaps two. Now there are more and more locomotives that work in multiple countries, e.g. TRAXX and Vectron. It's possible to rent carriages and trains. It's also possible to rent traction.
In some sense it's getting close to possible to do a startup in European rail. I'm thinking about the problem a lot.