Cost of doing business. A high cost (about 12% of their profits that year it looks like), but no one went to jail and they didn’t lose their corporate charter.
HSBC is not a US chartered bank.
There have been dozens of other fines.
Note also: Support for China’s Security Law for Hong Kong (2020)
But yeah, why is it still allowed to operate?
I was headhunted by them, but demurred.