Political structures exist to influence the world around them.
A thousand or even a few hundred years ago most people travelled very little and often were born, lived and died in the same village. At that time the village was the natural unit of organisation. As communications improved, with horses, trains, planes, internet the unit of political organisation had to scale up to cities, regions, nations and now supra national organisations like the EU
The nation state is an outdated concept that has lived its time. In a world where those we need to talk to are the US, China, Russia even big EU countries like France and Germany are too small so we need to scale up.
The nation-state is a current living concept that nation-states and their peoples for the most part are incredibly attached to. If you want to convince the peoples of the EU that is an outdated concept that has lived its time, that is a tough and long road ahead of you, or von der Layen if that is the road she’s pursuing but right now there’s plenty of national governments well beyond Hungary that have been displeased with von der Leyen specifically stepping on their toes.
Right now, the way the EU is constituted, the EU takes a backseat to national governments on most foreign policy. Trade is the biggest exception. Reversing that is as an ask she can make, but it’s an enormous ask that if the member states of the EU concede to, will still be an enormous concession, and it’s not something the EU is structurally positioned under its own Treaties and laws to either command nor demand.