(Perspective of an American who lives in a US Chinatown and speaks to many HKers, also went there last year)
Hong Kong is over.
Historically, it benefited from being one of the only open ports, proximate to China, but not in it. Good governance and rule of law (very important for mercantile activity, given how much finance, insurance, and complex legal codes around ownership / title / possession), nice real estate, etc.
Today, it feels like the PRC is playing the long game, and they're going to win -- they'll just hang up their hats and wait 50 years, only a generation or two, until they eventually take complete control of Hong Kong, maybe going as far as outright annexation. They're patient, determined, and focused in a way only a place ruled by a powerful, long-term oriented elite oligopoly can be (vs in the US, where we still can't fix Social Security, even though everyone knows it's a train wreck in the making, or build anything remotely resembling China's current high-speed rail network).
The real question I have is, what's going to happen in China when Xi Jinping (dictator for life) can no longer rule effectively? Will he willingly stop aside or is there going to be some kind of coup / violent overthrow if the CCP splits and can't decide whether or not it's time to replace him? That's what's got me thinking these days.