The US mortgage delinquency rate was 2.13% in Q1 2022
( https://fred.stlouisfed.org/series/DRSFRMACBS ). It was 4% in 2016, 3% in 2018. Why should an observer/investor be worried that "Non-performing loans [...] could reach as much as [...] 1.4% of the outstanding mortgage balance"?
The situation is a bit different. It's common in China to pay for unfinished apartments. So the bank has nothing to foreclose on, and the property development company becomes even less likely to finish the property. The fear is that more people will protest by stopping payment in a downward spiral.
Your numbers don't measure the same thing. Non-performing is a subset of delinquent, meaning likely to end in foreclosure. If you don't pay your mortgage, you go to delinquent and then a few months later to non-performing.
