I'm a year or two away from eligibility of permanent resident status here in HK and, while I obviously haven't hated living here enough yet to pull up stakes and move, I can't really agree with your assessment of HK as a great place.

The pollution is frighteningly terrible most of the year (some from vehicles here, some from coal-fired power plants here, and about 60% from industrial activities across the border on the Mainland), about half of the population endure a desperately low standard of living and live in sprawling public housing estates because they simply cannot afford to purchase or rent apartments of their own, the economy is run by a handful of tycoons that dominate every sector and drive the price of each and every good and service up, elections for the chief executive (local equivalent of mayor/governor) are "small circle" (a few hundred people, mostly pawns of the tycoons or pro-Beijing folks cast votes last time), etc.

It's a third world city with some British traditions that are being systematically expunged or, when that would likely draw too great of an outcry, gradually eroded under Beijing's rule.

Hong Kong has a far longer history of prominence then Dubai. It grew slower & it has lost its position slower. The underlying reasons for HK's importance have been dissolving. There is no reason to use HK as an intermediary for dealings with China. There is no reason not to establish an office in the mainland.

But being in slow relative decline meant has meant that they fared alright. (a) Decline Relative to China can still be reasonable growth. IE they can have a smaller share of a bigger pie. (b) The secondary industries: Tourism, financial services, consultancies etc. have had a chance to have a go on their own.