[dredmorbius]

The aircraft in question is being offered for a relatively short-range flight (London-Paris), 345 km (215 mi). Odds are good this flight configuration wouldn't be used on long-distance trans-oceanic flights.

Though it might be best-suited to short hops between islands, islands and mainlands, or across deep peninsulas. That's a somewhat limited set of markets.

For travel between heavily-populated continental points, ground-based rail would almost certainly be more efficient and practicable, and even in the case of the suggested London-Paris route, there is a ground-based alternative.