They saw the West's playbook

They really didn't. It's the equivalent of lending your cousin some old pickups, mortars and a few shotguns that were gathering dust for home defense. Our playbook for the defense of Taiwan is a VERY different beast entirely.

A weak world economy benefits China.

It really, really wouldn't - not that anyone really "wins", but some, including China, will certainly lose more than others. And if you're using National Interest as your source, keep in mind this is the same company that published Maria Butina and arguably leans moderately pro-Russian.

How many "made in China" products did each of us buy last month?

If you believe this is supporting your point, then you have a poor grasp of geo-economics.

In the current state of global affairs, they will prevail as the world's superpower, and that is a terrifying future to imagine.

Actually, it's more likely that India emerges in that role in the long run. Additionally, geography plays a significant role in force projection, especially naval - something that GREATLY favors the US for obvious reasons. Granted, that advantage shrinks somewhat depending on foreign power expansion into permanent bases along the African coast.