It’s been an effective method of sanctioning individuals and organizations so far. WeChat and Alipay isn’t worth a damn outside of PRC, and sanctioning a handful of pro-Beijing individuals isn’t likely to change that. Truth is, the United States still dominates the global financial infrastructure and being cut off from that is a difficult pill for most to swallow.
I guess. But what would the average citizen use? Cash? Seems likely that somebody would step in to be the de facto online transaction provider. And the government probably would want some way to financially tie HK to the mainland.