To be honest I would say the US is burning faster.

China is likely more volatile, if their government falls it will take a much shorter time.

That said, the US is at it's breaking point. Even if one sets aside Trump being a moron, the US simply slowly corroded away it's governmental infrastructure. (Lots of empty seats being left unfilled)

The US isn't likely to deal with crises much better than China. Hell, COVID-19 brought the federal government (read: The Trump admin and the part of the fed they control) to the brink of simply refusing to provide services to certain states.

Where the "United States of Canada" and "Jesusland" were once jokes, the prospect of several states leaving the union (or even being ejected) is far from improbable if things continue to escalate.