Historically, China was a big buyer and still a big holder of US gov debt, which to some extent led to the ultra-low interest rate environment.
Nowadays, China is still helping keep the US interest rate low, indirectly. I think by not providing good return opportunities, China is forcing money to go to other places, indirectly providing more money (with low return alternative) in the global market for the US gov.
It’s not just impacting foreign capital interested in China, but Chinese money as well.
Alternatively, if China has attractive opportunities all over the place, it will compete for global money one way or another.