If China steps up to the war plate, it will be horrible for everyone in the world. If they do happen to topple the US, you think they’re gonna stop with Taiwan? Or do you think the rest of the world with less then 1/10th the military might will somehow fend them off. This is a global issue.
Europe is increasingly irrelevant to the future of geopolitics.
The West is increasingly irrelevant to the future of geopolitics.
It may not happen overnight, but it will happen. The West is broke. It is becoming weaker and poorer by the day.
It will be like Japan or Germany in WW2 in many ways. It will be unable to replace losses of war-materiel fast enough to maintain its strength. After a few years, there won't be enough fighters, bombers, ships, soldiers, etc. to maintain a workable defence.
This is like saying Asia will be geopolitically irrelevant. It just can’t happen due to how much of the Earths landmass and resources it takes up.