To the world really, because we do not have to drive to Frankfurt first to use a proper airport.
I look forward to the Frankfurt-London rail link operated by Deutsche Bahn. Strange times, when the UK thinks about moving away from the EU and staying alone on their little island like in the good old times and yet London is nearly as close to Frankfurt as Frankfurt is to Berlin.
Actually i've recently had a chat with people from DB Strategy, they've said that the Frankfurt-London connection is now technically possible and has been tested, but the ICE that should be used on it has a lot of technical issues that push the chances of having technical issues on one trip to above 20%.
That is a reason why they have pushed that connection off into the undisclosed future.
He wasn't a technical person, but the way he described it was that everytime an ICE crosses a country border, it has to change the settings on how the train operates, to comply with local laws and standards. This is stuff like how rapidly it is supposed to brake, etc.
He says that there is a 1 in 10 chance that when doing that "settings-swap" some part of the train software crashes irrecoverably and the whole train has to be rebooted, which can take up to 15 minutes.
So when crossing from germany into belgium, then france, then uk and back again there would be a high chance that those trains would have to be rebooted somewhere along that track, and that would wreck havoc within the international train system.
