China is in no way an appropriate strategic, economic or military partner. Its is on the other side of the planet, it has only its own best interests in mind to make itself into a regional superpower that does EXACTLY what Trump and Putin does. Its economic system is the polar opposite of Europe, open and free market vs protectionist and state-controlled market). Militarily it is growing fast but is still highly regional with limited power projection (i.e. cannot help us).
Wanting to partner with China against US makes no sense, they are the primary financier of Russia with the deliberate intent on weakening Europe and distract us from competing with them globally. Not to mention that America isn’t our enemy, but Trump and his regime specifically, the vast (75%) majority of US is against the Greenland grab.
Decoupling will be gradual and take many years, unless things escalate and the EU decides to decouple without an alternative in place.
That would however be extremely costly and I think they want to avoid that.
The advantage of a sudden shift is of course that change will happen faster due to necessity. But as I mentioned, at a greatly increased cost.
The question is how long will Europe stand being humiliated by Trump every second day?