China hasn't sealed the deal yet. They've become vastly closer to matching the West, but there's still both a lot of poverty and economic uncertainty left to deal with which could knock them off track. It wasn't that long ago that Japan was seen in a similar light as China, but ultimately settled.
I think China also has another problem. They're not that great at exporting soft power. Sure, their skill at leveraging economic dominance is pretty good, but they're an incredibly insular culture compared to Spain, France, Britain, or America. China's external culture power is honestly pretty low, and I'm not sure they have the societal values to grow it unless there are major changes. Without that, could it truly claim geopolitical dominance? And if Chinese economic growth does stagnate, what do they have left if there's not high culture power?
There's also another issue. The age of colonialism permitted the forceful spread of Spanish, French, and English all over the world. And the three traded places as the lingua franca as time went on. But those three are also all related languages. Mandarin both is of an entirely different language family and uses a different written form, not even just a different alphabet. It was way easier for Spanish, French, and English dominance to pass between one another than it would be for it to pass from English to Mandarin.
I'm not saying it's impossible, but I'm still skeptical of these things. Our ability to project geopolitical futures has often been kind of...off. *glances at hundreds of stories of the Cold War continuing in perpetuity*