> The real issue is that I'm very unlikely to choose this option, no matter how convenient the booking
It's broader than just convenient booking, it's also integrated servicing, scheduling and infrastructure. With integrated scheduling you can get better connecting trains.
> > bahn.de will sell me (through an international website to which they redirect) a ticket from Frankfurt to London via Paris, an 8h40m trip costing 182 EUR one way for a date ~2 weeks out.
Frankfurt to Brussels is 3 hours, Brussels to London is 2 hours. It could be a 5 hour trip if the trains connected, very competitive to the 4-5 hours you mentioned. (And with existing technology the durations could be cut down by 30%). But if there's no connecting trains between the German-Belgian track, and the Belgian-UK track, then it will indeed take 8-9 hours.
I'd definitely rather sit on a train. Relative to airplanes you typically get:
- quiet
- cheap/available wifi
- spacious (leg room, work space)
- large windows
- easy access to your luggage (for work, food and recreation)
- boarding experience that's less frustrating
- boarding in a city centre as opposed to a peripheral airport
Price remains an issue, but it's also an issue of scale and value proposition. The Italian trains I've been on were simply vastly superior experiences to whatever flight I ever took and quite cost-competitive. Take Bologna to Napels, it's a 600km route that is 3h 20m by train for just 38 euros, central station to central station. Flights certainly don't win out here. By comparison, Frankfurt to London is 640km as the bird flies. It seems once things start crossing borders and you get into disconnected international tracks, scheduling, ticketing, infrastructure, prices and connections start to suck. But that's in part a solvable issue that can be largely mitigated. If Italy can do a 600km track for 30 euros in 3.3 hours, that should be a attainable across Europe with the proper strategy and investments within 20 years.
There's also the point of pricing in externalities for air flight, not doing so makes them unduly competitive. That's unlikely to last. Some countries are adding 10-20 euros to flight prices this year alone as a start, making 1-2 hour flights less interesting vs trains. Although I've read reports both ways (how flights are undertaxed, as well as how trains are already very subsidised) so I'm not sure on this point.
