Difficult to say. In a direct duel on a climb, I saw VDP once beat Van Aert on the cobblestones. On the "Oude Kwaremont" (Flanders 2021). A few km later, VDP was beaten by Asgreen at the finish...... Of course, VDP was better or ended before Van Aert in some races. As Van Aert did with VDP. I think, the difference is. Van Aert, even beaten by VDP or another rider, keeps going until the end to get a place of honor. Therefore it is visually very clear that he was defeated. But when VDP is released or defeated, he no longer insists and ends up in the bunch. For instance, Strade Bianche 2020, the Tourstage when VDP lost his yellow jersey, while Van Aert was defending his second place (or a possible yellow yersey) fighting to the finish, isolated, against Pogacar and a group of pursuers he just missed.
And, I'm pretty sure Van Aert, in form then, would have defeated VDP in the Tour of Brittain, in that fourth stage, on a terrible wallclimb. Where Van Aert has beaten Alaphilippe, Woods, Hayter, Dan Martin....