In HK, a lot of the taxi drivers are old guys who can barely read, don't speak English or mandarin, and are a real hassle to deal with unless you are a Cantonese speaker. A lot of the taxis have weird fare manipulation lookup tables instead of correct metering. Although the mass-transit oriented stored value card, Octopus, was established decades ago, you still can't use it in taxis. Further, if you want to top it up, you literally can't top it up with anything smaller than HKD50 (USD$9) even if your fare costs less and you only have small denomination local money. There are no electric taxis, but plenty of rich people own Teslas. If you ask 20 odd Hong Kong banks about cross-border RMB payment APIs (HK is supposed to be a financial center, after all) not a single bank can offer you one. In fact, just to open a regular bank account is now so difficult standard waits can exceed 2-3 months (and success is far from guaranteed).
So what does HK still have to offer?
(1) A legal environment under Beijing's auspices but with nominal resistance to mainland corruption and manipulation.
(2) Superior international financial connectivity and services if you can get a bank account.
(3) Liberal visa-free travel policies for people from most countries.
That's about it.