I think it's a telling statistic that since the handover, Hong Kong has gone from 18% of China's GDP to 3%. Granted, some of that may be the mainland playing games with GDP numbers, but HK isn't quite the same indispensable a golden-goose anymore.
[0] https://www.vox.com/2014/9/28/6857567/hong-kong-used-to-be-1...