Alright...but someone from Britain could, at least with sufficient notice, find cheaper tickets to those destinations (in Belgium and Holland; and the two places in Germany listed, Aachen and Cologne too) on the Eurostar via Brussels, I think.
If you're based in Paris(or somewhere beyond there in France) , or travelling from Paris as initial point of origin ....OK. But for people travelling from the UK...well, it might be worth looking at if all the cheap Eurostar tickets to Brussels have gone on a day when there are still some available to Paris. But probably not otherwise