I don't understand the article. They explain than going in and out of the airport is burdersome, and that taking the Eurostar from London to Amsterdam is a much better experience, except for the change in Brussels
A London to Amsterdam is currently 4 hours and 38 minutes (incl. a 47min change in Brussels). With a propre planning between Eurostar and Thalys, the route could be done in less than four hours.
Taking a flight, on the contrary, will likely be much longer if you include the time to go to the airport, arrive 90 minutes in advance, and the time to leave airport in Amsterdam. Eurostar seem to have a clear advantage here, with prices often competitive, especially if you include Snap tickets.
For a day or weekend trip to Amsterdam without hold luggage, 60 or even 45 minutes in advance is plenty (whereas, contra the article, 30 minutes before a Eurostar departure is not enough in standard class), and Schiphol airport is very organized and only a 20 minute train ride from central Amsterdam.
As I do very often, you can push that advance further. On London City flights, like I did sunday to Rotterdam, walking in under 30m works fine. If you have fasttrack and travel a lot (aka you know where to go in airports), for flights within the EU 90 minutes make no sense at all. Besides cancellations (my return flight to City was cancelled and moved to Heathrow which was a PITA) and the co2 pollution, I definitely prefer planes most of the time. The idea of a train sometimes appeals (even if it takes far more time): seeing the landscape for instance.
Fwiw, we did the math ourselves when living in London: Eurostar to Paris was a no brainer time saver, as was (pretty much) Eurostar to Brussels. But we opted to fly to Amsterdam - time lost at the airport was gained by the short flight.
This was influenced by us living in South London (Brixton). If we'd been closer to St Pancras / further from the airport, the math may have differed.
A London to Amsterdam is currently 4 hours and 38 minutes (incl. a 47min change in Brussels). With a propre planning between Eurostar and Thalys, the route could be done in less than four hours.
Taking a flight, on the contrary, will likely be much longer if you include the time to go to the airport, arrive 90 minutes in advance, and the time to leave airport in Amsterdam. Eurostar seem to have a clear advantage here, with prices often competitive, especially if you include Snap tickets.