Except he quite literally predicted it, held out for the sprint, and won. your whole narrative is based on your own belief of the riders' respective strengths, which is not what Asgreen thought about himself - and to everyone's shock, Asgreen did know more about himself than people on here did.
Asgreen also made the calculation that he felt more comfortable in a two up race than in a three, and that makes sense. A three is more difficult to control, and Asgreen felt/knew he wanted to have as much control over the situation as possible. Plus, Van der Poel could tell how weak Van Aert was, so would've followed every move Asgreen without giving too much regard to the fact he was leading out the (spent) Van Aert.
Your whole issue is that you're not taking into account just how good Asgreen was today. You're treating him as clearly worse than VdP, and someone whose best chance of a win would come by creating chaos and then riding away. But he proved that isn't the case.