There may be a bit of Eurovision Song Contest effect contributing slightly.
Don’t forget if you get the Eurostar from Amsterdam to St Pancras, there’s a passport check at Brussels which makes the journey slightly longer.
https://www.eurostar.com/uk-en/train/netherlands
”...On the return journey, you’ll need to take a Thalys train from Amsterdam Centraal or Rotterdam Centraal to Brussels-Midi/Zuid. On arrival at Brussels Midi/Zuid, you’ll need to go through security and have your passport checked before you hop on a Eurostar train back to St Pancras International.”